The current study examined the incremental validity of the clinical clusters from the Woodcock-Johnson III Tests of Cognitive Abilities (WJ-III COG) for predicting scores on the Woodcock-Johnson III Tests of Achievement (WJ-III ACH). All participants were children and adolescents (N = 4,722) drawn from the nationally representative WJ-III…

Proposes a new approach for classifying text documents into two disjoint classes. Highlights include a brief overview of document clustering; a data mining approach called the One Clause at a Time (OCAT) algorithm which is based on mathematical logic; vector space model (VSM); and comparing the OCAT to the VSM. (Author/LRW)

This study examines the organization and development of 5 domains of reasoning (categorical, quantitative, spatial, causal, and propositional) and the construct validity of a test designed to measure development from early adolescence to early adulthood. The theory underlying the test is first summarized and the conceptual design of the test is…

Any attempt to describe every job position and the activities contained in it would yield a confusing mass of information. Consequently, industrial psychologists have generated methods for classifying occupational positions into a smaller number of jobs or job families. Based on prior research it has been concluded that different kinds of job…

A Monte Carlo study evaluated the effectiveness of three rules of classifying objects into clusters: nearest neighbor classification; nearest centroid assignment; and quadratic discriminant analysis. Results suggest that the nearest neighbor rule is a useful tool for assessing the validity of the clustering procedure of J. H. Ward (1963). (SLD)

Predictive discriminant analysis involves a technique used in multivariate classification, i.e., in predicting membership in well-defined groups for units on which multiple measures are available. The validation (assessment) of group membership predictions pertains to two problems: estimating true proportions of correct classifications (i.e., hit…

The role of the coauthor relationship in the structure of informal communications networks within disciplines is explored, and the validity of coauthor graphs used to map these relationships is tested for both small and large databases. (CLB)

Discusses the intellectual structure of the sciences and describes a study that was conducted to test the usefulness of author cocitation analysis for empirically deriving groupings of intellectual leaders in the field of sociology. Results are contrasted with traditional subjective methods of codification of a field. (35 references) (LRW)

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…

The plotting of multivariate data using computer line-printers has become a popular means of quickly representing multidimensional data. While many plotting programs are available, there is a paucity of research regarding the validity and reliability of interpretations made by viewing such graphics. This study explores the validity of four…