Assessment of Incomplete Effort With the California Verbal Learning Test

Abstract

The false-positive rates of 2 formulas for the detection of incomplete effort on the California Verbal Learning Test (CVLT; Delis, Kramer, Kaplan, & Ober, 1987) were evaluated in a sample of 134 patients with traumatic head injury (THI) who had been carefully screened to eliminate any individuals who might be expected to have financial incentives for poor performance. One formula incorrectly identified only 7.46% of the sample as providing incomplete effort, confirming its potential usefulness in clinical settings. The other formula fared much worse, misidentifying an unacceptably high 18.66% of the sample. Lower levels of education were found to increase the likelihood of false-positive results with that formula. It is concluded that the CVLT holds promise for the evaluation of incomplete effort after THI but only within the context of a more comprehensive neuropsychological evaluation.