Chapter 4: Evaluating Teachers Through Student Test Scores: A Cautionary Tale

This chapter examines the premise that student test scores in the United States can reliably be useful instruments for teacher effectiveness. Using the concepts of reliability and validity, and exploring all the arguments used to make the case for a positive relationship between teacher effectiveness and student test scores, each proposed rationale is refuted. Studies consistently show very low correlations. About 90% of the variance in student test scores is attributable to factors other than teachers. The conclusion is that student test scores are totally unreliable as standards that solely measure teaching effectiveness. The implications are that similar results would likely obtain in other countries should such misplaced reasoning prevail.