Rekitting the Wechsler Paired-Associate Task: the Waterford Index

The Waterford Index provides a new scoring system for the Wechsler paired-associate task. Item performances across successive trials were coded so as to reflect the psychological phenomena of learning, forgetting and item effects (N = 50). The Index describes two rules for differentiating between cases of cognitive impairment and non-impairment. Rule 1 contrasts the respective contributions of learning and forgetting. Rule 2 takes account of cases characterized by a high proportion of correct responses. Against a criterion index based on performances on other psychological tests of organic dysfunction, the Waterford Index yielded higher predictive efficiencies than associated with other Wechsler indices, intelligence, and age.