{"id":3506,"date":"2022-03-02T15:50:01","date_gmt":"2022-03-02T15:50:01","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/?post_type=chapter&#038;p=3506"},"modified":"2022-04-09T04:05:42","modified_gmt":"2022-04-09T04:05:42","slug":"forming-connections-in-2b","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/chapter\/forming-connections-in-2b\/","title":{"raw":"Forming Connections in 2B: Sampling Bias","rendered":"Forming Connections in 2B: Sampling Bias"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Objectives for this activity<\/h3>\r\nDuring this activity, you will:\r\n<ul>\r\n \t<li style=\"font-weight: 400;\" aria-level=\"1\">Identify sampling bias.<\/li>\r\n \t<li style=\"font-weight: 400;\" aria-level=\"1\">Describe a random and representative sample from a population.<\/li>\r\n<\/ul>\r\n<\/div>\r\nIn\u00a0<em>What to Know [2B]<\/em>, you saw four methods for sampling data from a population. In this activity be invited to think more deeply about the relationship between a population and a sample.\u00a0 You will determine a population and sample based on a research question, and identify potential issues with sampling bias. You'll also see that selecting a representative sample from a population is important for generalizing conclusions on the population.\r\n<h2>Would You Like a Sample?<\/h2>\r\nA student at a local high school in Florida is interested in doing a research project about student diversity in the three public high schools in her county. She wants to investigate the proportion of public high school students in her county who self-identify as American Indian\/Alaskan native, Asian, Black, Hispanic, White, or Multi-ethnic.\r\n\r\n<img class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001948\/Picture76-300x200.jpg\" alt=\"A group of young people smiling for a picture\" width=\"300\" height=\"200\" \/>\r\n\r\nWhat do you think the population of interest is? Turn to a partner to share your answer then discuss together the options available if the student wants to take a representative sample from this population to answer Question 1.\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 1<\/h3>\r\nWhat is the population of interest? What should she consider if she wants to take a representative sample from this population?\r\n\r\n[reveal-answer q=\"776054\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"776054\"]Consider what you know about identifying a population. What kind of sampling method have you seen that tends to produce a representative sample?[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox tryit\">\r\n<h3>Guidance<\/h3>\r\n<span style=\"background-color: #e6daf7;\">[Intro: What did you come up with as a good method for her to take a representative sample? In\u00a0<em>What to Know [2B], <\/em>the preview for this activity, four sampling methods were given. Did you chose one of those? In this activity, you'll learn to identify sampling bias and understand how to describe a random and representative sample from a population. Work in pairs to answer Question 2 - 5 to identify sources of bias in the given scenarios.\u00a0]<\/span>\r\n\r\n<\/div>\r\n<h3>Sampling Bias<\/h3>\r\nWhenever we take a sample from a population, there is the potential of introducing sampling bias. It is important to be aware of potential sources of bias and take steps to minimize the chance that sampling bias is present in the way that we sample.\r\n\r\nHere are the four main sources of bias to consider when sampling from a population:\r\n<ul>\r\n \t<li style=\"font-weight: 400;\" aria-level=\"1\"><strong>Undercoverage<\/strong> occurs when some groups of the population are left out of the sampling process and the individuals in these groups do not have an equal chance of being selected for the sample. For example, a sample survey of households in a country may miss people who are homeless, prison inmates, or students living in dorms.<\/li>\r\n \t<li style=\"font-weight: 400;\" aria-level=\"1\"><strong>Non-response bias<\/strong> occurs when an individual chosen for a sample cannot be contacted or decides to not participate in the study or research. This type of bias occurs after the sample has been selected and can create potential bias in the data collected.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"font-weight: 400;\" aria-level=\"1\"><strong>Response bias<\/strong> is defined as a systemic pattern of inaccurate responses to questions. This type of bias can occur when a person does not understand a question or feels influenced to respond to a question in a certain way. Response bias can also occur as a result of the wording of questions that are of a sensitive nature.<\/li>\r\n \t<li style=\"font-weight: 400;\" aria-level=\"1\">A <strong>voluntary response bias<\/strong> is another form of bias because the sample is not random or representative of the population. The people who volunteer for a study or survey may be more inclined to respond to questions or report certain behaviors.<\/li>\r\n<\/ul>\r\nWe need to be aware of the potential sources of bias that will prevent us from appropriately generalizing sample results to the population. Work in pairs to answer Questions 2 - 5\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 2<\/h3>\r\nLet\u2019s say the student takes a simple random sample of students from her high school and asks those students about their race\/ethnicity. Describe any potential sources of bias in her sampling method.\r\n\r\n[reveal-answer q=\"730694\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"730694\"]Were all the high schools in the population of interest included? [\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 3<\/h3>\r\nAssume the student creates a questionnaire that asks about race\/ethnicity and then asks for volunteers at all three high schools to take the questionnaire. Describe any potential sources of bias in her sampling method.\r\n\r\n[reveal-answer q=\"182661\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"182661\"]How can voluntary response be a potential source of bias?[\/hidden-answer]\r\n\r\n<\/div>\r\nHopefully you are beginning to understand how to recognize a source of potential sampling bias. By looking at key words and phrases, like\u00a0<em>volunteer\u00a0<\/em>and\u00a0<em>questionnaire<\/em>, or by realizing that only one group from a population has been sampled, you are able to identify a method that may tend to produce unrepresentative samples.\r\n\r\nAs you answer Question 4, refer to the list of sampling methods given in the preview page. Here is a summary of those methods.\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>\u00a0divides 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>\u00a0selects a sample most accessible to the researcher.<\/li>\r\n<\/ul>\r\nWhich of these do you feel would most likely tend to produce random samples from this particular population of three high schools?\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 4<\/h3>\r\nSince there are three public high schools in the student\u2019s county, describe how she might select a representative sample. Explain how the method you chose minimizes bias.\r\n\r\n[reveal-answer q=\"804226\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"804226\"]What do you think? Remember what you learned about different sampling methods in the preview page.[\/hidden-answer]\r\n\r\n<\/div>\r\nFinally, discuss Question 5 together in pairs and record your responses.\r\n<div class=\"textbox key-takeaways\">\r\n<h3>question 5<\/h3>\r\nThis student wants to use the results of her study to describe the race\/ethnicity of all high school-aged students in her county (ages 14\u201318). What is the population of interest now? Is the sample of students described in Question 4 appropriate for this population? Explain.\r\n\r\n[reveal-answer q=\"656542\"]Hint[\/reveal-answer]\r\n[hidden-answer a=\"656542\"]What do <em>you\u00a0<\/em>think?[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox tryit\">\r\n<h3>Guidance<\/h3>\r\n<span style=\"background-color: #e6daf7;\">[Wrap-up: Did you find it challenging to come up with the best sampling method for the student's population of three high schools to answer Question 4? You might have attempted to eliminate one or more methods first. Convenience sampling tends to produce unrepresentative samples, so that would be the first method to eliminate. Simple random sampling and systematic sampling both require the enrollment of all three schools to be merged first, then sampled. Both of these methods help to ensure that each individual of the population has an equivalent chance of being selected in a sample. But could these methods tend to blur distinctions of race and ethnicity that occur naturally in each schools unique populations? If we eliminate them, we are left with stratified sampling. What characteristic of this method could make it the most appropriate one to use? These types of questions are necessary to performing as strong a statistical analysis as possible. In some cases, we may find that not matter what method we use, there is little chance that the population of interest we have chosen could be used to generalize results to an even larger population, as you may have discovered in your discussion of Question 5. We'll be learning about experimental design in the next section. The concepts and skills you've obtained during this activity will be helpful as you explore further.]\u00a0<\/span>\r\n\r\n<\/div>\r\n&nbsp;","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Objectives for this activity<\/h3>\n<p>During this activity, you will:<\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\">Identify sampling bias.<\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\">Describe a random and representative sample from a population.<\/li>\n<\/ul>\n<\/div>\n<p>In\u00a0<em>What to Know [2B]<\/em>, you saw four methods for sampling data from a population. In this activity be invited to think more deeply about the relationship between a population and a sample.\u00a0 You will determine a population and sample based on a research question, and identify potential issues with sampling bias. You&#8217;ll also see that selecting a representative sample from a population is important for generalizing conclusions on the population.<\/p>\n<h2>Would You Like a Sample?<\/h2>\n<p>A student at a local high school in Florida is interested in doing a research project about student diversity in the three public high schools in her county. She wants to investigate the proportion of public high school students in her county who self-identify as American Indian\/Alaskan native, Asian, Black, Hispanic, White, or Multi-ethnic.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5738\/2022\/01\/12001948\/Picture76-300x200.jpg\" alt=\"A group of young people smiling for a picture\" width=\"300\" height=\"200\" \/><\/p>\n<p>What do you think the population of interest is? Turn to a partner to share your answer then discuss together the options available if the student wants to take a representative sample from this population to answer Question 1.<\/p>\n<div class=\"textbox key-takeaways\">\n<h3>question 1<\/h3>\n<p>What is the population of interest? What should she consider if she wants to take a representative sample from this population?<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q776054\">Hint<\/span><\/p>\n<div id=\"q776054\" class=\"hidden-answer\" style=\"display: none\">Consider what you know about identifying a population. What kind of sampling method have you seen that tends to produce a representative sample?<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox tryit\">\n<h3>Guidance<\/h3>\n<p><span style=\"background-color: #e6daf7;\">[Intro: What did you come up with as a good method for her to take a representative sample? In\u00a0<em>What to Know [2B], <\/em>the preview for this activity, four sampling methods were given. Did you chose one of those? In this activity, you&#8217;ll learn to identify sampling bias and understand how to describe a random and representative sample from a population. Work in pairs to answer Question 2 &#8211; 5 to identify sources of bias in the given scenarios.\u00a0]<\/span><\/p>\n<\/div>\n<h3>Sampling Bias<\/h3>\n<p>Whenever we take a sample from a population, there is the potential of introducing sampling bias. It is important to be aware of potential sources of bias and take steps to minimize the chance that sampling bias is present in the way that we sample.<\/p>\n<p>Here are the four main sources of bias to consider when sampling from a population:<\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><strong>Undercoverage<\/strong> occurs when some groups of the population are left out of the sampling process and the individuals in these groups do not have an equal chance of being selected for the sample. For example, a sample survey of households in a country may miss people who are homeless, prison inmates, or students living in dorms.<\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><strong>Non-response bias<\/strong> occurs when an individual chosen for a sample cannot be contacted or decides to not participate in the study or research. This type of bias occurs after the sample has been selected and can create potential bias in the data collected.<\/li>\n<\/ul>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><strong>Response bias<\/strong> is defined as a systemic pattern of inaccurate responses to questions. This type of bias can occur when a person does not understand a question or feels influenced to respond to a question in a certain way. Response bias can also occur as a result of the wording of questions that are of a sensitive nature.<\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\">A <strong>voluntary response bias<\/strong> is another form of bias because the sample is not random or representative of the population. The people who volunteer for a study or survey may be more inclined to respond to questions or report certain behaviors.<\/li>\n<\/ul>\n<p>We need to be aware of the potential sources of bias that will prevent us from appropriately generalizing sample results to the population. Work in pairs to answer Questions 2 &#8211; 5<\/p>\n<div class=\"textbox key-takeaways\">\n<h3>question 2<\/h3>\n<p>Let\u2019s say the student takes a simple random sample of students from her high school and asks those students about their race\/ethnicity. Describe any potential sources of bias in her sampling method.<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q730694\">Hint<\/span><\/p>\n<div id=\"q730694\" class=\"hidden-answer\" style=\"display: none\">Were all the high schools in the population of interest included? <\/div>\n<\/div>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>question 3<\/h3>\n<p>Assume the student creates a questionnaire that asks about race\/ethnicity and then asks for volunteers at all three high schools to take the questionnaire. Describe any potential sources of bias in her sampling method.<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q182661\">Hint<\/span><\/p>\n<div id=\"q182661\" class=\"hidden-answer\" style=\"display: none\">How can voluntary response be a potential source of bias?<\/div>\n<\/div>\n<\/div>\n<p>Hopefully you are beginning to understand how to recognize a source of potential sampling bias. By looking at key words and phrases, like\u00a0<em>volunteer\u00a0<\/em>and\u00a0<em>questionnaire<\/em>, or by realizing that only one group from a population has been sampled, you are able to identify a method that may tend to produce unrepresentative samples.<\/p>\n<p>As you answer Question 4, refer to the list of sampling methods given in the preview page. Here is a summary of those methods.<\/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>\u00a0divides 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>\u00a0selects a sample most accessible to the researcher.<\/li>\n<\/ul>\n<p>Which of these do you feel would most likely tend to produce random samples from this particular population of three high schools?<\/p>\n<div class=\"textbox key-takeaways\">\n<h3>question 4<\/h3>\n<p>Since there are three public high schools in the student\u2019s county, describe how she might select a representative sample. Explain how the method you chose minimizes bias.<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q804226\">Hint<\/span><\/p>\n<div id=\"q804226\" class=\"hidden-answer\" style=\"display: none\">What do you think? Remember what you learned about different sampling methods in the preview page.<\/div>\n<\/div>\n<\/div>\n<p>Finally, discuss Question 5 together in pairs and record your responses.<\/p>\n<div class=\"textbox key-takeaways\">\n<h3>question 5<\/h3>\n<p>This student wants to use the results of her study to describe the race\/ethnicity of all high school-aged students in her county (ages 14\u201318). What is the population of interest now? Is the sample of students described in Question 4 appropriate for this population? Explain.<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q656542\">Hint<\/span><\/p>\n<div id=\"q656542\" class=\"hidden-answer\" style=\"display: none\">What do <em>you\u00a0<\/em>think?<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox tryit\">\n<h3>Guidance<\/h3>\n<p><span style=\"background-color: #e6daf7;\">[Wrap-up: Did you find it challenging to come up with the best sampling method for the student&#8217;s population of three high schools to answer Question 4? You might have attempted to eliminate one or more methods first. Convenience sampling tends to produce unrepresentative samples, so that would be the first method to eliminate. Simple random sampling and systematic sampling both require the enrollment of all three schools to be merged first, then sampled. Both of these methods help to ensure that each individual of the population has an equivalent chance of being selected in a sample. But could these methods tend to blur distinctions of race and ethnicity that occur naturally in each schools unique populations? If we eliminate them, we are left with stratified sampling. What characteristic of this method could make it the most appropriate one to use? These types of questions are necessary to performing as strong a statistical analysis as possible. In some cases, we may find that not matter what method we use, there is little chance that the population of interest we have chosen could be used to generalize results to an even larger population, as you may have discovered in your discussion of Question 5. We&#8217;ll be learning about experimental design in the next section. The concepts and skills you&#8217;ve obtained during this activity will be helpful as you explore further.]\u00a0<\/span><\/p>\n<\/div>\n<p>&nbsp;<\/p>\n","protected":false},"author":493460,"menu_order":42,"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-3506","chapter","type-chapter","status-publish","hentry"],"part":3418,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/chapters\/3506","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":10,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/chapters\/3506\/revisions"}],"predecessor-version":[{"id":4334,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/chapters\/3506\/revisions\/4334"}],"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\/3506\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/wp\/v2\/media?parent=3506"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/pressbooks\/v2\/chapter-type?post=3506"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/wp\/v2\/contributor?post=3506"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/lumen-danacenter-statsmockup\/wp-json\/wp\/v2\/license?post=3506"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}