{"id":3504,"date":"2022-03-02T15:49:45","date_gmt":"2022-03-02T15:49:45","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/?post_type=chapter&#038;p=3504"},"modified":"2022-04-08T01:53:34","modified_gmt":"2022-04-08T01:53:34","slug":"what-to-know-about-2b","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/chapter\/what-to-know-about-2b\/","title":{"raw":"What to Know About 2B: Sampling Bias","rendered":"What to Know About 2B: Sampling Bias"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>learning GOALS<\/h3>\r\nAt the end of this page, you should feel comfortable performing these skills:\r\n<ul>\r\n \t<li>Define sample vs. population.<\/li>\r\n \t<li>Identify the different sampling methods.<\/li>\r\n<\/ul>\r\n<\/div>\r\nIn the previous section,\u00a0<em>Random Sampling<\/em>, you learned that some sampling methods were biased, and can produced samples unrepresentative of the population from which they are selected.\u00a0In the\u00a0next\u00a0activity, you will need to be able to distinguish between a sample and a population and identify different sampling methods. Prepare for that now by formally defining the population and sample, then learning about four common sampling methods.\r\n<h2>Sampling Methods<\/h2>\r\nIn a moment, you'll learn about four sampling methods commonly used in research. It is important to note that not all statistical questions can be investigated using purely unbiased methods.\u00a0 Therefore, acknowledging\u00a0bias in the sampling method is crucial to interpreting the analysis. Before we introduce these methods, let's formally define what we mean by\u00a0populations and samples.\r\n<h3>Population vs. Sample<\/h3>\r\nIn the previous section,\u00a0<em>Random Sampling<\/em>, you identified populations and parameters from descriptions of studies. The population was the entire group of interest and the parameter was a numerical summary describing a characteristic of that group.\r\n\r\nIn real life, it is usually hard to collect data on an entire population. Therefore, samples are used in research studies to collect data to make inferences about a population. Collecting data from a sample is less time consuming and less costly than collecting data from an entire population.\r\n\r\nAnswer Questions 1 and 2 now to define the terms\u00a0<strong>population<\/strong> and <strong>sample.\u00a0<\/strong>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Question 1<\/h3>\r\nWhat is the entire group of individuals\/animals\/items that we want to draw conclusions about during a research study?\r\n<ol>\r\n \t<li>a) Population<\/li>\r\n \t<li>b) Sample<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"338045\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"338045\"]See the text above for guidance.[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 2<\/h3>\r\nWhat is the specific group of individuals\/animals\/items that we collect data from for a research study?\r\n<ol>\r\n \t<li>a) Population<\/li>\r\n \t<li>b) Sample<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"414341\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"414341\"]See the text above for guidance.[\/hidden-answer]\r\n\r\n<\/div>\r\n<h3>Sampling Methods<\/h3>\r\nThere are four common sampling methods used in research. These sampling methods include: simple random sampling, systematic sampling, stratified sampling, and convenience sampling.\r\n\r\n<strong>Simple Random Sampling:<\/strong> In simple random sampling, every sample of a given size has the same chance of being selected; this results in every individual of the population having an equal chance of being selected. Recall that random number generators are used to select samples. In the following figure, the random number generator selected numbers 24, 22, 27, 25, and 13, resulting in the highlighted individuals being selected for the sample.\r\n\r\n<span style=\"background-color: #ffff99;\">[See the original DC page for how the images below need to convey the information]<\/span>\r\n<table>\r\n<tbody>\r\n<tr>\r\n<td style=\"width: 49px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>1<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>2<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>3<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>4<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>5<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>6<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>7<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>8<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>9<\/strong><\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 49px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>10<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>11<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>12<\/strong><\/td>\r\n<td style=\"width: 50px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>13<\/strong><\/span><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>14<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>15<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>16<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>17<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>18<\/strong><\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 49px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>19<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>20<\/strong><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>21<\/strong><\/td>\r\n<td style=\"width: 50px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>22<\/strong><\/span><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>23<\/strong><\/td>\r\n<td style=\"width: 50px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>24<\/strong><\/span><\/td>\r\n<td style=\"width: 50px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>25<\/strong><\/span><\/td>\r\n<td style=\"width: 50px;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>26<\/strong><\/td>\r\n<td style=\"width: 50px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>27<\/strong><\/span><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<div class=\"textbox tryit\">\r\n<h3>Video Placement<\/h3>\r\n<span style=\"background-color: #e6daf7;\">Simple Random Sampling - a very brief demonstration<\/span>\r\n\r\n<\/div>\r\n<strong>Systematic Sampling:<\/strong> In systematic sampling, every individual in the population is given a number and individuals are chosen at regular intervals, with a random starting point (usually among the first several). The following figure illustrates a systematic sample where every 4th individual is selected, starting at the 3rd individual (starting point selected at random). The individuals selected for the sample are highlighted.\r\n<table style=\"height: 473px;\">\r\n<tbody>\r\n<tr style=\"height: 133px;\">\r\n<td style=\"height: 133px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>1<\/strong><\/td>\r\n<td style=\"height: 133px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>2<\/strong><\/td>\r\n<td style=\"height: 133px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>3<\/strong><\/span><\/td>\r\n<td style=\"height: 133px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>4<\/strong><\/td>\r\n<td style=\"height: 133px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>5<\/strong><\/td>\r\n<td style=\"height: 133px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>6<\/strong><\/td>\r\n<td style=\"height: 133px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>7<\/strong><\/span><\/td>\r\n<td style=\"height: 133px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>8<\/strong><\/td>\r\n<td style=\"height: 133px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>9<\/strong><\/td>\r\n<\/tr>\r\n<tr style=\"height: 170px;\">\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>10<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>11<\/strong><\/span><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>12<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>13<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>14<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>15<\/strong><\/span><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>16<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>17<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>18<\/strong><\/td>\r\n<\/tr>\r\n<tr style=\"height: 170px;\">\r\n<td style=\"height: 170px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>19<\/strong><\/span><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>20<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>21<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>22<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>23<\/strong><\/span><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>24<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>25<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>26<\/strong><\/td>\r\n<td style=\"height: 170px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>27<\/strong><\/span><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<div class=\"textbox tryit\">\r\n<h3>Video Placement<\/h3>\r\n<span style=\"background-color: #e6daf7;\">Systematic Sampling - a very brief demonstration<\/span>\r\n\r\n<\/div>\r\n<strong>Stratified Sampling:<\/strong> In stratified sampling, a population is divided into two or more groups (called strata) according to some criterion (i.e., geographic location, grade level, age group, income group, etc.), and a sample is selected from each strata using simple random sampling or systematic sampling.\r\n<table>\r\n<tbody>\r\n<tr>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>1<\/strong><\/td>\r\n<td><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>2<\/strong><\/span><\/td>\r\n<td><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>3<\/strong><\/span><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>4<\/strong><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>5<\/strong><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>6<\/strong><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>7<\/strong><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>8<\/strong><\/td>\r\n<td><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>9<\/strong><\/span><\/td>\r\n<\/tr>\r\n<tr>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>10<\/strong><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>11<\/strong><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>12<\/strong><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>13<\/strong><\/td>\r\n<td><span style=\"background-color: #ffff00;\"><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>14<\/strong><\/span><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>15<\/strong><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>16<\/strong><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>17<\/strong><\/td>\r\n<td><strong><img class=\"alignnone wp-image-1090 \" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong>\r\n\r\n<strong>18<\/strong><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<table>\r\n<tbody>\r\n<tr>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>1<\/strong><\/td>\r\n<td><span style=\"background-color: #ffff00;\"><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>2<\/strong><\/span><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>3<\/strong><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>4<\/strong><\/td>\r\n<td><span style=\"background-color: #ffff00;\"><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>5<\/strong><\/span><\/td>\r\n<td><span style=\"background-color: #ffff00;\"><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>6<\/strong><\/span><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>7<\/strong><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>8<\/strong><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>9<\/strong><\/td>\r\n<\/tr>\r\n<tr>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>10<\/strong><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>11<\/strong><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>12<\/strong><\/td>\r\n<td><span style=\"background-color: #ffff00;\"><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/span>\r\n\r\n<span style=\"background-color: #ffff00;\"><strong>13<\/strong><\/span><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>14<\/strong><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>15<\/strong><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>16<\/strong><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>17<\/strong><\/td>\r\n<td><img class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/>\r\n\r\n<strong>18<\/strong><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<div class=\"textbox tryit\">\r\n<h3>Video Placement<\/h3>\r\n<span style=\"background-color: #e6daf7;\">Stratified Sampling - a very brief demonstration<\/span>\r\n\r\n<\/div>\r\n<strong>Convenience Sampling:<\/strong> A convenience sample is a sample of individuals who are most accessible to the researcher. A convenience sample is usually not random or representative of the population. This is an example of a biased sampling method because it has a tendency to produce samples that are not representative of the population. For example, you take a sample of your friends because it is easy to collect information about them.\r\n<div class=\"textbox tryit\">\r\n<h3>Video Placement<\/h3>\r\n<span style=\"background-color: #e6daf7;\">Convenience Sampling - a very brief demonstration<\/span>\r\n\r\n<\/div>\r\n<h3>Identifying Sampling Methods<\/h3>\r\nIn Questions 3\u20137, you'll read a brief description of a study, then identify the sampling method used. See the video below for a demonstration of how to differentiate between the methods in a description of a study.\r\n<div class=\"textbox tryit\">\r\n<h3>Video Placement<\/h3>\r\n<span style=\"background-color: #e6daf7;\">[worked example: a 3-instructor video that offers examples of the four sampling methods and clues that will help distinguish which is being used.] <\/span>\r\n\r\n<\/div>\r\nLet's summarize key features of each of the four common sampling methods we discussed.\r\n<ul>\r\n \t<li><strong>Simple random sampling<\/strong>\u00a0assigns a number to every member of the population then uses a random number generator to select a sample.<\/li>\r\n \t<li><strong>Systematic sampling<\/strong>\u00a0assigns a number to every member of the population then choses individuals from the population at regular intervals (e.g. every 4th individual from a randomly selected starting point).<\/li>\r\n \t<li><strong>Stratified sampling<\/strong> divides a population into groups via some criterion then uses simple random selection or systematic selection to collect a sample from each group.<\/li>\r\n \t<li><strong>Convenience sampling<\/strong> selects a sample most accessible to the researcher.<\/li>\r\n<\/ul>\r\nNow you try the questions below. Be sure to check the feedback to assess your understanding.\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 3<\/h3>\r\n3) A college instructor wants to know what students think of her teaching methods, so she surveys the 10 students who sit in the front row. What kind of sample is this?\r\n<ol>\r\n \t<li>a) Stratified sample<\/li>\r\n \t<li>b) Simple random sample<\/li>\r\n \t<li>c) Convenience sample<\/li>\r\n \t<li>d) Systematic sample<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"586674\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"586674\"]Use the video and summary above to guide you.[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 4<\/h3>\r\n4) At a high school assembly, you need to sample students to understand their views about the new school uniforms. You decide to group students by grade (9th, 10th, 11th, and 12th) and then sample students within each grade using a random number generator. What kind of sample is this?\r\n<ol>\r\n \t<li>a) Stratified sample<\/li>\r\n \t<li>b) Simple random sample<\/li>\r\n \t<li>c) Convenience sample<\/li>\r\n \t<li>d) Systematic sample<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"941561\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"941561\"]Use the video and summary above to guide you.[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 5<\/h3>\r\n5) A research team wants to determine the GPA of college students at a university. The team samples 20 students at random from each of the following majors: English, Science, Computer Science, Engineering, Math, and Fine Arts. What kind of sample is this?\r\n<ol>\r\n \t<li>a) Stratified sample<\/li>\r\n \t<li>b) Simple random sample<\/li>\r\n \t<li>c) Convenience sample<\/li>\r\n \t<li>d) Systematic sample<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"685819\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"685819\"]Use the video and summary above to guide you.[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 6<\/h3>\r\n6) A company that makes hand sanitizer is interested in understanding the work\/life balance culture of the company from the perspective of the employees. Each employee is assigned a number in the company database from 1 to 1,200. A random number generator is used to select 75 numbers, and the employees with those numbers are asked to take part in a focus group. What kind of sample is this?\r\n<ol>\r\n \t<li>a) Stratified sample<\/li>\r\n \t<li>b) Simple random sample<\/li>\r\n \t<li>c) Convenience sample<\/li>\r\n \t<li>d) Systematic sample<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"13029\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"13029\"]Use the video and summary above to guide you.[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 7<\/h3>\r\n7) The same hand sanitizer company is interested in conducting focus groups of employees to better understand the work\/life balance culture of the company. They decided to create a list in alphabetical order of all their employees by their last name. Then, they select a sample of employees by selecting every 8th person on the list for the sample. What kind of sample is this?\r\n<ol>\r\n \t<li>a) Stratified sample<\/li>\r\n \t<li>b) Simple random sample<\/li>\r\n \t<li>c) Convenience sample<\/li>\r\n \t<li>d) Systematic sample<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"155174\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"155174\"]Use the video and summary above to guide you.[\/hidden-answer]\r\n\r\n<\/div>\r\n<h2>Summary<\/h2>\r\nIn this\u00a0<em>What to Know\u00a0<\/em>page,\u00a0you defined the terms\u00a0<em>population<\/em> and\u00a0<em>sample<\/em>\u00a0to understand that in statistics, data is collected on a sample drawn from a population because it is often impossible due to time and financial constraints to collect data on an entire population.\u00a0\u00a0You also learned to identify four common sampling methods and saw that convenience sampling is usually a biased method. Let\u2019s summarize where these concepts appeared in the questions for this page.\r\n<ul>\r\n \t<li>In Questions 1 - 2, you defined sample vs. population.<\/li>\r\n \t<li>In Questions 3 - 7, you identified the 4 different common sampling methods.<\/li>\r\n<\/ul>\r\nHopefully, you have a basic understanding of these ideas now. You can come back to this page any time to refresh the definitions and methods. Now it\u2019s time to move on to\u00a0<em>Forming Connections<\/em>!","rendered":"<div class=\"textbox learning-objectives\">\n<h3>learning GOALS<\/h3>\n<p>At the end of this page, you should feel comfortable performing these skills:<\/p>\n<ul>\n<li>Define sample vs. population.<\/li>\n<li>Identify the different sampling methods.<\/li>\n<\/ul>\n<\/div>\n<p>In the previous section,\u00a0<em>Random Sampling<\/em>, you learned that some sampling methods were biased, and can produced samples unrepresentative of the population from which they are selected.\u00a0In the\u00a0next\u00a0activity, you will need to be able to distinguish between a sample and a population and identify different sampling methods. Prepare for that now by formally defining the population and sample, then learning about four common sampling methods.<\/p>\n<h2>Sampling Methods<\/h2>\n<p>In a moment, you&#8217;ll learn about four sampling methods commonly used in research. It is important to note that not all statistical questions can be investigated using purely unbiased methods.\u00a0 Therefore, acknowledging\u00a0bias in the sampling method is crucial to interpreting the analysis. Before we introduce these methods, let&#8217;s formally define what we mean by\u00a0populations and samples.<\/p>\n<h3>Population vs. Sample<\/h3>\n<p>In the previous section,\u00a0<em>Random Sampling<\/em>, you identified populations and parameters from descriptions of studies. The population was the entire group of interest and the parameter was a numerical summary describing a characteristic of that group.<\/p>\n<p>In real life, it is usually hard to collect data on an entire population. Therefore, samples are used in research studies to collect data to make inferences about a population. Collecting data from a sample is less time consuming and less costly than collecting data from an entire population.<\/p>\n<p>Answer Questions 1 and 2 now to define the terms\u00a0<strong>population<\/strong> and <strong>sample.\u00a0<\/strong><\/p>\n<div class=\"textbox key-takeaways\">\n<h3>Question 1<\/h3>\n<p>What is the entire group of individuals\/animals\/items that we want to draw conclusions about during a research study?<\/p>\n<ol>\n<li>a) Population<\/li>\n<li>b) Sample<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q338045\">Hint<\/span><\/p>\n<div id=\"q338045\" class=\"hidden-answer\" style=\"display: none\">See the text above for guidance.<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>question 2<\/h3>\n<p>What is the specific group of individuals\/animals\/items that we collect data from for a research study?<\/p>\n<ol>\n<li>a) Population<\/li>\n<li>b) Sample<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q414341\">Hint<\/span><\/p>\n<div id=\"q414341\" class=\"hidden-answer\" style=\"display: none\">See the text above for guidance.<\/div>\n<\/div>\n<\/div>\n<h3>Sampling Methods<\/h3>\n<p>There are four common sampling methods used in research. These sampling methods include: simple random sampling, systematic sampling, stratified sampling, and convenience sampling.<\/p>\n<p><strong>Simple Random Sampling:<\/strong> In simple random sampling, every sample of a given size has the same chance of being selected; this results in every individual of the population having an equal chance of being selected. Recall that random number generators are used to select samples. In the following figure, the random number generator selected numbers 24, 22, 27, 25, and 13, resulting in the highlighted individuals being selected for the sample.<\/p>\n<p><span style=\"background-color: #ffff99;\">[See the original DC page for how the images below need to convey the information]<\/span><\/p>\n<table>\n<tbody>\n<tr>\n<td style=\"width: 49px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>1<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>2<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>3<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>4<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>5<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>6<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>7<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>8<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>9<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 49px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>10<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>11<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>12<\/strong><\/td>\n<td style=\"width: 50px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>13<\/strong><\/span><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>14<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>15<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>16<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>17<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>18<\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 49px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>19<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>20<\/strong><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>21<\/strong><\/td>\n<td style=\"width: 50px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>22<\/strong><\/span><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>23<\/strong><\/td>\n<td style=\"width: 50px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>24<\/strong><\/span><\/td>\n<td style=\"width: 50px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>25<\/strong><\/span><\/td>\n<td style=\"width: 50px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>26<\/strong><\/td>\n<td style=\"width: 50px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"283\" height=\"300\" \/>27<\/strong><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<div class=\"textbox tryit\">\n<h3>Video Placement<\/h3>\n<p><span style=\"background-color: #e6daf7;\">Simple Random Sampling &#8211; a very brief demonstration<\/span><\/p>\n<\/div>\n<p><strong>Systematic Sampling:<\/strong> In systematic sampling, every individual in the population is given a number and individuals are chosen at regular intervals, with a random starting point (usually among the first several). The following figure illustrates a systematic sample where every 4th individual is selected, starting at the 3rd individual (starting point selected at random). The individuals selected for the sample are highlighted.<\/p>\n<table style=\"height: 473px;\">\n<tbody>\n<tr style=\"height: 133px;\">\n<td style=\"height: 133px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>1<\/strong><\/td>\n<td style=\"height: 133px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>2<\/strong><\/td>\n<td style=\"height: 133px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>3<\/strong><\/span><\/td>\n<td style=\"height: 133px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>4<\/strong><\/td>\n<td style=\"height: 133px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>5<\/strong><\/td>\n<td style=\"height: 133px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>6<\/strong><\/td>\n<td style=\"height: 133px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>7<\/strong><\/span><\/td>\n<td style=\"height: 133px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>8<\/strong><\/td>\n<td style=\"height: 133px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>9<\/strong><\/td>\n<\/tr>\n<tr style=\"height: 170px;\">\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>10<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>11<\/strong><\/span><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>12<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>13<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>14<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>15<\/strong><\/span><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>16<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>17<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>18<\/strong><\/td>\n<\/tr>\n<tr style=\"height: 170px;\">\n<td style=\"height: 170px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>19<\/strong><\/span><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>20<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>21<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>22<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>23<\/strong><\/span><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>24<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>25<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>26<\/strong><\/td>\n<td style=\"height: 170px; width: 53px;\"><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>27<\/strong><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<div class=\"textbox tryit\">\n<h3>Video Placement<\/h3>\n<p><span style=\"background-color: #e6daf7;\">Systematic Sampling &#8211; a very brief demonstration<\/span><\/p>\n<\/div>\n<p><strong>Stratified Sampling:<\/strong> In stratified sampling, a population is divided into two or more groups (called strata) according to some criterion (i.e., geographic location, grade level, age group, income group, etc.), and a sample is selected from each strata using simple random sampling or systematic sampling.<\/p>\n<table>\n<tbody>\n<tr>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>1<\/strong><\/td>\n<td><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>2<\/strong><\/span><\/td>\n<td><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>3<\/strong><\/span><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>4<\/strong><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>5<\/strong><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>6<\/strong><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>7<\/strong><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>8<\/strong><\/td>\n<td><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>9<\/strong><\/span><\/td>\n<\/tr>\n<tr>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>10<\/strong><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>11<\/strong><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>12<\/strong><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>13<\/strong><\/td>\n<td><span style=\"background-color: #ffff00;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>14<\/strong><\/span><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>15<\/strong><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>16<\/strong><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>17<\/strong><\/td>\n<td><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1090\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001927\/Picture68-283x300.png\" alt=\"A blue icon of a person's sillhouette\" width=\"53\" height=\"56\" \/><\/strong><\/p>\n<p><strong>18<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<tbody>\n<tr>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>1<\/strong><\/td>\n<td><span style=\"background-color: #ffff00;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>2<\/strong><\/span><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>3<\/strong><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>4<\/strong><\/td>\n<td><span style=\"background-color: #ffff00;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>5<\/strong><\/span><\/td>\n<td><span style=\"background-color: #ffff00;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>6<\/strong><\/span><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>7<\/strong><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>8<\/strong><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>9<\/strong><\/td>\n<\/tr>\n<tr>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>10<\/strong><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>11<\/strong><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>12<\/strong><\/td>\n<td><span style=\"background-color: #ffff00;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/span><\/p>\n<p><span style=\"background-color: #ffff00;\"><strong>13<\/strong><\/span><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>14<\/strong><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>15<\/strong><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>16<\/strong><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>17<\/strong><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1094\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12002537\/Picture65-281x300.png\" alt=\"A green icon of a person's sillhouette\" width=\"52\" height=\"56\" \/><\/p>\n<p><strong>18<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<div class=\"textbox tryit\">\n<h3>Video Placement<\/h3>\n<p><span style=\"background-color: #e6daf7;\">Stratified Sampling &#8211; a very brief demonstration<\/span><\/p>\n<\/div>\n<p><strong>Convenience Sampling:<\/strong> A convenience sample is a sample of individuals who are most accessible to the researcher. A convenience sample is usually not random or representative of the population. This is an example of a biased sampling method because it has a tendency to produce samples that are not representative of the population. For example, you take a sample of your friends because it is easy to collect information about them.<\/p>\n<div class=\"textbox tryit\">\n<h3>Video Placement<\/h3>\n<p><span style=\"background-color: #e6daf7;\">Convenience Sampling &#8211; a very brief demonstration<\/span><\/p>\n<\/div>\n<h3>Identifying Sampling Methods<\/h3>\n<p>In Questions 3\u20137, you&#8217;ll read a brief description of a study, then identify the sampling method used. See the video below for a demonstration of how to differentiate between the methods in a description of a study.<\/p>\n<div class=\"textbox tryit\">\n<h3>Video Placement<\/h3>\n<p><span style=\"background-color: #e6daf7;\">[worked example: a 3-instructor video that offers examples of the four sampling methods and clues that will help distinguish which is being used.] <\/span><\/p>\n<\/div>\n<p>Let&#8217;s summarize key features of each of the four common sampling methods we discussed.<\/p>\n<ul>\n<li><strong>Simple random sampling<\/strong>\u00a0assigns a number to every member of the population then uses a random number generator to select a sample.<\/li>\n<li><strong>Systematic sampling<\/strong>\u00a0assigns a number to every member of the population then choses individuals from the population at regular intervals (e.g. every 4th individual from a randomly selected starting point).<\/li>\n<li><strong>Stratified sampling<\/strong> divides a population into groups via some criterion then uses simple random selection or systematic selection to collect a sample from each group.<\/li>\n<li><strong>Convenience sampling<\/strong> selects a sample most accessible to the researcher.<\/li>\n<\/ul>\n<p>Now you try the questions below. Be sure to check the feedback to assess your understanding.<\/p>\n<div class=\"textbox key-takeaways\">\n<h3>question 3<\/h3>\n<p>3) A college instructor wants to know what students think of her teaching methods, so she surveys the 10 students who sit in the front row. What kind of sample is this?<\/p>\n<ol>\n<li>a) Stratified sample<\/li>\n<li>b) Simple random sample<\/li>\n<li>c) Convenience sample<\/li>\n<li>d) Systematic sample<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q586674\">Hint<\/span><\/p>\n<div id=\"q586674\" class=\"hidden-answer\" style=\"display: none\">Use the video and summary above to guide you.<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>question 4<\/h3>\n<p>4) At a high school assembly, you need to sample students to understand their views about the new school uniforms. You decide to group students by grade (9th, 10th, 11th, and 12th) and then sample students within each grade using a random number generator. What kind of sample is this?<\/p>\n<ol>\n<li>a) Stratified sample<\/li>\n<li>b) Simple random sample<\/li>\n<li>c) Convenience sample<\/li>\n<li>d) Systematic sample<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q941561\">Hint<\/span><\/p>\n<div id=\"q941561\" class=\"hidden-answer\" style=\"display: none\">Use the video and summary above to guide you.<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>question 5<\/h3>\n<p>5) A research team wants to determine the GPA of college students at a university. The team samples 20 students at random from each of the following majors: English, Science, Computer Science, Engineering, Math, and Fine Arts. What kind of sample is this?<\/p>\n<ol>\n<li>a) Stratified sample<\/li>\n<li>b) Simple random sample<\/li>\n<li>c) Convenience sample<\/li>\n<li>d) Systematic sample<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q685819\">Hint<\/span><\/p>\n<div id=\"q685819\" class=\"hidden-answer\" style=\"display: none\">Use the video and summary above to guide you.<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>question 6<\/h3>\n<p>6) A company that makes hand sanitizer is interested in understanding the work\/life balance culture of the company from the perspective of the employees. Each employee is assigned a number in the company database from 1 to 1,200. A random number generator is used to select 75 numbers, and the employees with those numbers are asked to take part in a focus group. What kind of sample is this?<\/p>\n<ol>\n<li>a) Stratified sample<\/li>\n<li>b) Simple random sample<\/li>\n<li>c) Convenience sample<\/li>\n<li>d) Systematic sample<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q13029\">Hint<\/span><\/p>\n<div id=\"q13029\" class=\"hidden-answer\" style=\"display: none\">Use the video and summary above to guide you.<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>question 7<\/h3>\n<p>7) The same hand sanitizer company is interested in conducting focus groups of employees to better understand the work\/life balance culture of the company. They decided to create a list in alphabetical order of all their employees by their last name. Then, they select a sample of employees by selecting every 8th person on the list for the sample. What kind of sample is this?<\/p>\n<ol>\n<li>a) Stratified sample<\/li>\n<li>b) Simple random sample<\/li>\n<li>c) Convenience sample<\/li>\n<li>d) Systematic sample<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q155174\">Hint<\/span><\/p>\n<div id=\"q155174\" class=\"hidden-answer\" style=\"display: none\">Use the video and summary above to guide you.<\/div>\n<\/div>\n<\/div>\n<h2>Summary<\/h2>\n<p>In this\u00a0<em>What to Know\u00a0<\/em>page,\u00a0you defined the terms\u00a0<em>population<\/em> and\u00a0<em>sample<\/em>\u00a0to understand that in statistics, data is collected on a sample drawn from a population because it is often impossible due to time and financial constraints to collect data on an entire population.\u00a0\u00a0You also learned to identify four common sampling methods and saw that convenience sampling is usually a biased method. Let\u2019s summarize where these concepts appeared in the questions for this page.<\/p>\n<ul>\n<li>In Questions 1 &#8211; 2, you defined sample vs. population.<\/li>\n<li>In Questions 3 &#8211; 7, you identified the 4 different common sampling methods.<\/li>\n<\/ul>\n<p>Hopefully, you have a basic understanding of these ideas now. You can come back to this page any time to refresh the definitions and methods. Now it\u2019s time to move on to\u00a0<em>Forming Connections<\/em>!<\/p>\n","protected":false},"author":493460,"menu_order":41,"template":"","meta":{"_candela_citation":"[]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-3504","chapter","type-chapter","status-publish","hentry"],"part":3418,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/chapters\/3504","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/wp\/v2\/users\/493460"}],"version-history":[{"count":12,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/chapters\/3504\/revisions"}],"predecessor-version":[{"id":4300,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/chapters\/3504\/revisions\/4300"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/parts\/3418"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/chapters\/3504\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/wp\/v2\/media?parent=3504"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/chapter-type?post=3504"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/wp\/v2\/contributor?post=3504"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/wp\/v2\/license?post=3504"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}