Clinical decision making: Use of selection ratios to predict intelligence

Illustrated the concept of selection ratios for large clinical settings. Four Draw-A-Person (DAP) variables were used to predict intelligence (revised beta) in 601 institutionalized drug addicts (mean age, 27.8 yrs). The simple correlations between each of the variables and beta, as well as the multiple correlation between the 4 variables and beta, were generally weak. However, prediction of the extreme scores on intelligence (upper and lower quartiles and deciles of the distribution) was possible with some degree of accuracy. Results indicate that a test with low predictability across the entire distribution can often be used quite effectively for identifying poor or excellent performers. (PsycINFO Database Record (c) 2006 APA, all rights reserved).