We’ve previously written about the use of the Wonderlic aptitude test on NFL draft prospects, pointing out that the popular press and NFL fans as a whole have often unfairly dismissed aptitude tests as irrelevant to future gridiron success. This seems to be based on jock stereotypes about the sport and on a misunderstanding of how tests, and predictive tools in general, work. Virtually every article about the Wonderlic test at the NFL draft mentions Dan Marino, who bombed the Wonderlic and went on to a Hall of Fame career, as evidence that the tests aren’t predictive of success in football. However, this type of anecdotal evidence clearly holds no weight when statistically determining whether or not a test works.
This Saturday is the NFL draft, which means that NFL scouts have spent the past months going over 40-yard dash times and college game tapes, and fans have debated which prospect would be the best fit for their team. It also means it's time for media and fans to recycle the usual punchlines about the folly of using an aptitude test like the Wonderlic on NFL prospects. Football, more than any other American team sport, is about physicality, and the idea that performance on an aptitude test could have much to do with success on the football field seems absurd. Skeptics point out that a low Wonderlic score didn't prevent Dan Marino from becoming one of the most prolific passers in history, or Vince Young from making the Pro Bowl in his rookie year. When Criteria works with customers to gather evidence for the validity of our employment tests at their organization, we sometimes hear similar anecdotes. I've often heard HR managers express concern that "one of our best performers did poorly on the test." (Criteria has an aptitude test, the CCAT, that is similar to the Wonderlic.) Such reactions are understandable, but the measure of a test's predictive validity can't be judged from one test score--the only meaningful way to measure a test's ability to predict productivity is to study the correlations between test scores and job performance across a broad sample of people. Based on this standard, the Wonderlic may be a better predictor of performance in the NFL than you might think.