Introduction

Knowledge, Technology &; Policy -     

The validity of verbal protocols

The reactivity of a "think aloud" verbal protocol and the veridicality of different retrospective protocols were tested over four dissimilar tasks. Generating a concurrent protocol altered accuracy in two tasks, simple addition and a choice between two gambles, and generally prolonged response times. Such reactivity partially qualifies the dominant theory of protocol generation (Ericsson & Simon, 1984). Retrospective protocols yielded substantial forgetting or fabrication in all tasks, supporting the consensus on the nonveridicality of these methods. It is concluded that protocol validity should be based on an empirical check rather than on theory-based assurances.     

The sensitivity of the Bender-Gestalt Test as a screening instrument for neuropsychological impairment in older adults

We investigated the sensitivity of the Bender (1938) Visual-Motor Gestalt Test (BGT) using the Halstead-Reitan Neuropsychological Battery (HRB) as the criterion for cortical dysfunction. We studied 95 subjects over age 55 who had been diagnosed as having dementia or pseudodementia. Subjects were classified as mild, moderately, or severely impaired on the HRB and as impaired or unimpaired on the BGT. The results indicated that the BGT is less sensitive (36%) than was expected when used on an impaired geriatric population. The data further indicated that false negatives occurred more frequently with the BGT when individuals had mild neuropsychological impairment. Less frequent misclassifications occurred as the severity of impairment on HRB indices increased.