Adaptive Behavior Scale, Part Two: predictive efficiency of severity and frequency scores.

Severity and frequency of occurrence methods of scoring the Adaptive Behavior Scale, Part Two, were compared using ratings for seven groups of mentally retarded persons. Comparisons involved separately correlating the two methods with independently obtained clinical impressions of symptomatology. The severity scoring system predicted approximately 11 percent more of the variance in the criterion than did frequency scores. These results provide considerable construct and predictive validity for the severity scoring system.