Sunday, March 18, 2012

The role of luck in the math SAT

The math SAT, for example, has limited replicability at the high end. Obtaining an 800 score usually requires making zero mistakes when answering 54 questions at a rate of one minute and 18 seconds per question. Making just three mistakes will drop a student to the 710–750 range. Consequently, it is not surprising that students who get a perfect 800 and then retake the SAT only average 752 on the retake. This is in the 97th percentile, and it is only a little higher than the 741 average achieved by students who retake the math SAT after scoring 760.
--Ashley Swanson and Glenn Ellison, Journal of Economic Perspectives, on fuzzy measurement