This study described an explicit multidimensional scaling (MDS) model for profile data, the Profile Analysis via Multidimensional Scaling (PAMS) model. It also illustrated the application of this model to the study of the structure of cognitive ability patterns using the Woodcock-Johnson Psychoeducational Battery-Revised (WJPB-R; 1989; 1991) and used the bootstrap technique to estimate the standard errors of the MDS coordinates. Data came from 176 adults in the norming sample of the WJPB-R. The example demonstrates that, within the context of the model in the first equation in the paper, scale values are test parameter estimates and can be interpreted in terms of prototypical profile patterns (and mirror image patterns) corresponding to dimensions. Observed profile patterns are represented as linear combinations of the prototypes. Person parameters are interpreted with respect to these same prototypical profile patterns. Profile level parameters quantify individual differences in overall profile height. Correspondence indices quantify the degree of match between observed profiles and dimension prototypes. As illustrated, correspondence indices can be used to study associations between match to prototypes and external variables. (Contains 4 tables, 6 figures, and 11 references.) (SLD)
