Three methods for grouping items in an opinion survey were compared for their utility in subscale construction: rational organization according to content, factor analysis, and multidimensional scaling. Only subscales based on factor analysis could be refined to meet the criteria of reliability, additivity, and interpretability simultaneously. (SV)

Multidimensional scaling (MDS) and Pathfinder techniques for assessing changes in the structural representation of a knowledge domain were studied with relatedness ratings collected from 72 Spanish college students. Comparison of student and expert similarity measures indicate that MDS and graph theoretic approaches are valid techniques. (SLD)

Three approaches to the graphic representation of similarity and dissimilarity matrices are compared and contrasted. Specifically, Kruskal's multidimensional scaling, Johnson's hierarchical clustering, and Waern's graphing techniques are employed to depict, in two dimensions, data representing the structure of a set of botanical concepts. Each of…