3 METHODOLOGICAL ISSUES IN THE DEVELOPMENT OF OBSERVER-RATED BEHAVIORRATING-SCALES - EXPERIENCE FROM THE DEVELOPMENT OF THE RATING-SCALE FOR AGGRESSIVE-BEHAVIOR IN THE ELDERLY

Rating scales are one of the most important sources of information bot h in psychiatric research and clinical management. During the developm ent of the Rating Scale for Aggressive Behaviour in the Elderly (RAGE) and evaluation of its psychometric properties, we employed techniques to study three methodological issues which we discuss in this paper. These data were collected on 125 in-patients on six psychogeriatric wa rds. The first methodological issue was the effect on reliability of d ifferent intervals of time between test and retest and was studied by spacing the retest 6 hours, 7 days and 14 days after the test. The sec ond issue was the effect of a ward checklist on inter-rater reliabilit y. The results show that reliability was significantly improved by the use of the checklist. The third issue was the evaluation of the clini cal validity of the rating scale using direct observational data as th e validating criterion. Although time-consuming, we conclude that even simple observation studies generate valuable information.