Overview

• Students will practice comparing distributions of a quantitative variable across groups by creating dotplots and histograms using the DCMP Data Analysis Tools.
• The activity uses a dataset from the 2010–2012 American Community Survey that reports the median salaries for recent college graduates for 172 college majors, as well as the major category (i.e., discipline) of each major.
• This activity connects back to histograms, dotplots, and describing distributions and prepares students for boxplots.
• V2, V1, C1, S2, C4, O2, C2 ← Link to EBTP descriptions 

Prerequisite assumptions

Students should be able to do each of the following after completing the What to Know assignment.

• Compare centers of distributions of a quantitative variable.
• Compare the spread in distributions of a quantitative variable.

Intended goals for this activity

After completing this activity, students should understand that histograms and dotplots can be used to compare distributions of a quantitative variable across groups. They should be able to compare the center, shape, and spread of distributions of a quantitative variable across groups.

Synchronous Delivery and Activity Flow

The sample activity delivery below assumes a face-to-face class meeting but can be adapted to a fully online or hybrid delivery by using break-out rooms for pairs and small groups.

Frame the activity (3 minutes)

• Question 1 is set up for a think-pair-share approach. Students can take a minute to think about their own major choice and then share with their neighbors. The instructor can then ask a few students to share their thoughts.
• After think-pair-share in Question 1, have a class discussion and write down which variables may play a role in a student’s major choice (e.g., percent of students who get a job in their major).
• Transition to the in-class activity by briefly discussing the Objectives for the activity.

Activity Flow (18 minutes)

• The entire activity can be done in small groups. If students are sharing devices in groups, intermittently remind students to switch who is controlling the tools so that all students get practice creating the plots using technology.
• Students should have access to the DCMP Data Analysis Tools.
• Questions 2 and 3 could be done as a class discussion where the instructor projects the dataset with a projector. View the dataset as a class and point out the distinction between the major itself and the major category. The text also supports this for students working on their own. V2
• Be sure that students in class are using the graphs and not the descriptive statistics to identify and compare center and spread. The app displays descriptive statistics, but they won’t be covered until later. Ask guiding questions such as, “How can you find the median using the dotplot?” or “Which dot on the plot corresponds to the median?”
• Check in with a brief whole group discussion after Quesions 11 and 12 to summarize the understanding.

Wrap-up/transition (5 minutes)

• Close the activity by having a few students share their answers to Question 13. V1
• Have students refer back to the Objectives for the activity and identify ones they recognized completing. S2, C4, O2
• Assign the homework or Practice and any What to Know pages for the Forming Connections activities you plan to complete in the next class meeting. C2