Bell, Richard C.Lumsden, James2011-02-102011-02-101980Bell, Richard & Lumsden, James. (1980). Test length and validity. Applied Psychological Measurement, 4, 165-170. doi:10.1177/014662168000400203doi:10.1177/014662168000400203https://hdl.handle.net/11299/100028The effect of test length on predictive validity is examined empirically by successively omitting the poorest items and by calculating the correlations between the reduced test scores and the criterion. It was found, for four tests, that the curve of validity against test length had a very gentle slope for the longer tests and that all tests could be reduced by more than 60% without appreciable decreases in validity.enArticle