Measuring Speed, Ability, or Motivation: A Comment on Goldhammer(2015)

摘要

Most people are aware that talent does not guarantee success in case one is lazy. This is also true for the performance in achievement tests that depends on, among other factors, achievement potential (ability) and willingness to achieve (test-taking motivation) of the test taker (Wigfield & Eccles, 2000). The interaction of ability and motivation ("skill and will"; Eklof, 2010) determines the effective ability of a test taker-that is, his or her actual level of capability that allows the test taker to solve a problem correctly or incorrectly. While effective ability and effective speed are related to accuracy and response times, there is no unique relationship of effective ability and effective speed with the level of ability and motivation of the test taker. Different combinations of motivation and ability are supposed to generate the same effective ability and speed. This is problematic insofar as motivation is thought to be an unstable trait that depends on the testing context (Richardson, Abraham, & Bond, 2012). In case motivation changes differentially from one testing context to another, the subjects' order with respect to effective ability might change and it would be hard to conclude which individual performs best. Hence, one may ask whether it is possible to disentangle the effects of motivation and ability on speed and accuracy in order to assess ability in its pure form-thereby losing any information about the level of motivation that might also be an important determinant of future performance.