Study shows weak correlation between student test scores and teacher performance

Published on Tuesday, May 20, 2014

TestingSometimes who pays for a study is as telling as the results of the study.

The Bill and Melinda Gates Foundation funded the research that generated the report, “Instructional Alignment as a Measure of Teaching Quality.” The researchers also used data from the Foundation’s Measures of Effective Teaching study to perform their work.

Given the Gates Foundation’s support for using student test data to evaluate teachers, it’s interesting to note that this study concluded that how students perform on state assessments is only weakly connected to instructional content or quality.

Morgan S. Polikoff from the University of Southern California and Andrew C. Porter from the University of Pennsylvania were the authors of this study, which recently appeared in Educational Evaluation and Policy Analysis, a peer-reviewed journal of the American Educational Research Association.

According to Polikiff and Porter, the low correlation between test results and teacher quality raises the question of what inferences can made on the basis of value-added assessment data.

“If [value-added models] are not meaningfully associated with either the content or quality of instruction, what are they measuring?” the authors wrote. They also noted that their study is just the latest contribution to a growing body of literature “suggesting state tests may not be up to the task of differentiating effective from ineffective (or aligned from misaligned) teaching….”

“Especially as standardized tests are used for an increasing array of purposes, including evaluating the performance of individual teachers, it is essential that researchers verify that tests can indeed detect differences in what and how well teachers teach,” Polikoff and Porter concluded.


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