Analytics Stories

CHAPTER 10Is Anderson Elementary School a Bad School?

Every year, third-graders in the state of Indiana take a standardized test to measure their academic progress. The test name changes all the time, but in 2018, the test was called the ISTEP+ test and consisted of two sections: Math and ELA (English Language Arts). We obtained the fraction of students at every Indiana public school who passed both parts of the test from the Indiana Department of Education (DoE) website (www.doe.in.gov/accountability/find-school-and-corporation-data-reports). We summarized these results in the file ISTEPTestsReg.xlsx. An average of 54% of all students taking the test passed both sections of the test. At Anderson Elementary School in Anderson, Indiana, only 36% of students passed both sections of the test. We take it as a given (although I don't think it is a good idea) that a school's quality can be entirely measured by how the students perform on standardized tests. The standard deviation of pass rates by school is 18%, so Anderson Elementary students performed nearly one standard deviation below average. At first glance, this indicates that Anderson Elementary is not getting the job done. However, we must ask if other factors exist besides school quality, such as family income, that might influence students' test performance.

How Can We Adjust for Family Income?

Consider two schools (1 and 2) that are entirely equal in their ability for preparing students for the ISTEP+ test. If School ...