Math Lesson Topic

Finding regression lines; the meaning of the “r” value; discussion on the relationship between correlation and causation

Social Justice Lesson Topic

Exploring Differences — a look at the relationship between postal codes and test scores

Resource

www.EdGap.org 

Lesson Plan

1. In small groups, give students 5-10 minutes to explore the www.EdGap.org  website without instruction.  Have students respond back with “What did you notice?” and “What do you wonder?”  Clarify ACT scoring system and SAT scoring system points.
2. Have student groups choose a variable to explore that is presented in the website (median household income, percent of unemployment rate, percent of children in 2-parent households, percent of college-educated parents).  Create a table of 20-30 different highschools and record their postal code, SAT/ACT score average, and the variable of interest.
3. Have students graph the data (talk about appropriate scales, guessing what the line will look like before plotting points).  Estimate the “r” value for their equations.
4. Have students run a linear regression on the data.  Note the equation and its associated “r” value.  Compare that to what was predicted from the graph.
5. Do a gallery walk of the groups’ graphs.  Have students look for patterns among the graphs, and brainstorm why those patterns might exist.
6. Discussion topic: Many colleges rely heavily on standardized test scores to determine whether a student should be admitted, because higher test scores have been correlated with higher levels of success in college.  Do you agree with this practice? Why or why not? What does this have to do with the previous exercise?  Consider how thee data speaks to structural injustices of high-stakes standardized testing and ways to empower students to address inequities.
7. Review the concept of “correlation does not imply causation”.  Talk about how the data does not prove a cause-and-effect relationship between test scores and socioeconomic information. Explore/brainstorm underlying causes that might influence the relationship (i.e. level of support, opportunity for upper-division courses, higher pay and incentive to recruit teachers, etc.)

(Ideas from Lesson 7.4 in High School Mathematics Lessons to Explore, Understand, and Respond to Social Injustice by Robert Q. Berry III, Basil M. Conway IV, Brian R. Lawler, John W. Staley, and colleagues)