Reliability analyses of the Luria-Nebraska Neuropsychological Battery factor scales by diagnostic group: a follow-up study.

The 30 scales developed from scalewise factor analyses of the items of the Luria-Nebraska Neuropsychological Battery were subjected to internal consistency analyses by means of coefficient alpha for a mixed brain-damaged group and neurologically normal groups of alcoholic and schizophrenic or schizoaffective disorder patients. Thirty-seven per cent of the factor scales failed to reach a 0.70 coefficient alpha level for the mixed brain damaged group, but that figure was reduced to 23% with use of scales based on an orthogonal factor solution for the Receptive Speech scale. Further refinement of the internally consistent factor scales was recommended. Internal consistency values were too low for the factor scales with the alcoholic and psychotic samples to recommend their clinical use with these groups. Methodological issues in the derivation and application of the factor scales were discussed.