THE MEASUREMENT OF CHILDRENS EXPOSURE TO VIOLENCE - A RASCH ANALYSIS

Current methods for assessing children's level of exposure to violence (ETV) generate non-linear scores whereas linear, interval level measu rement is required in order to make valid inferences about group diffe rences or change across time. Ordinal items can, however, be converted to a linear scale through the use of item response modelling. ETV res ponse data from a demographically diverse sample of forty-nine subject s (29 F, 20 M) ranging in age from 9 to 24 years (M = 17.6 years) was examined for its fit to the Rasch item response model for rating scale s. The Rasch model constructs a linear measure for ETV by using ordina l response data as realizations of the probabilities of item endorseme nt given the level of item extremity and the exposure level of the per son taking the item. The resulting person measures and item calibratio ns are on the same scale. Results show that these data fit the Rasch m odel quite well. In addition, the hierarchical ordering of item diffic ulty is consistent with our expectations and, thus, provides some evid ence for construct validity of the scale. The experience with ETV sugg ests that item response models such as Rasch may profitably be applied to other multi-item assessments of social behaviour and experience.