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Summary:
Data from normative samples (ages 6-17, N = 467) produce internal consistency subscale estimates that range from .74 to .93 with a very high total scale estimate (.96). These data suggest a strong single factor underlying the measure which is useful since the total score is typically used to track change. One index of discriminant validity is the striking difference between average total Y-OQ scores from community normal, outpatient, and inpatient samples. Prediction of membership in a clinical (inpatient & outpatient) or normal population based on total Y-OQ means using traditional cutscores yield an average classification accuracy of 85 percent. Inpatient status can be most reliably predicted (90.5%) followed by community normals and outpatients (85% & 81% respectively). Finally, high correlations exist between the Y-OQ total and subscale scores and frequently used assessment instruments.