The Right Coast

December 15, 2004
 
Teacher Cheating
By Mike Rappaport

This is really quite interesting. There is a reason why Steven Levitt is one of the hottest economists these days. Here is an excerpt from the summary supplied by Mahalanobis:

To address [whether teachers cheat to improve their students' test scores], we once again turn to data from the Chicago Public Schools, for which we have the question-by-question answers given by every student in grades 3-7 taking the Iowa Test of Basic Skills (ITBS) over an eight year period. In the first paper,(4) we develop and test an algorithm for detecting cheating. Our approach uses two types of cheating indicators: unexpected test score fluctuations and unusual patterns of answers for students within a classroom. Teacher cheating increases the likelihood that students in a classroom will experience large, unexpected increases in test scores one year, followed by very small test score gains (or even declines) the following year. Teacher cheating, especially if done in an unsophisticated manner, is also likely to leave tell-tale signs in the form of blocks of identical answers, unusual patterns of correlations across student answers within the classroom, or unusual response patterns within a student's exam (for example, a student who answers a number of very difficult questions correctly while missing many simple questions).

Empirically, we [found] evidence of cheating in approximately 4 to 5 percent of the classes in our sample.

[Subsequently, retesting under audited conditions was conducted.] The results of the retesting provided strong support for the effectiveness of the cheating detection algorithm. Classrooms suspected of cheating experienced large declines in test scores (on average about one grade equivalent, although in some cases the fall in mean classroom test scores was over three grade equivalents) when retested under controlled conditions. In contrast, classrooms not suspected of cheating a priori maintained virtually all of their gains on the retest. As a consequence of these audits and subsequent investigations, disciplinary action was brought against a substantial number of teachers, test administrators, and principals.