The May-June edition of the APA's journal American Psychologist contains an important new study on the effectiveness and validity of employment testing. The study examines the predictive validity of testing in both educational and employment settings. There's a good summary of the study's findings on my favorite statistics blog. Essentially, the study shows that employment aptitude tests are a generally valid way of predicting a wide variety of aspects of job performance. It also contains encouraging conclusions about the fairness of aptitude tests.
While most of the conclusions of the study will not be surprising to people familiar with the field of employment testing, my sense is that this is an important study because of the amount of evidence it considers. The study is a meta-analysis (a review of many different studies) and may be the most comprehensive attempt to examine the effectiveness and validity of employment testing since Hunter and Schmidt's seminal study in the late 1990s.
If you want to cough up $12 to read the whole study you can do so here. I'll probably get into the details of the study in subsequent posts.