Describes a new combinatorial algorithm for fitting additive trees to proximity data. This generalized triples method examines all triples of objects of interest in relation to the remaining set of objects to be clustered. The procedure is illustrated, and a simulation study shows its advantages. (SLD)

In his early exposition of path analysis, Duncan (1966) noted that the method "provides a calculus for indirect effects." Despite the interest in indirect causal effects, most users treat them as if they are population parameters and do not test whether they are statistically significant. Sobel (1982) has recently derived the asymptotic…

This paper provides a description of an online Rorschach interpretation algorithm for the Exner comprehensive system, as well as a study conducted to evaluate the validity of the online interpretive algorithm. The user, systems, and equipment specifications for the algorithm are explained, and the potential advantages of its use to enhance…

To make training cost-effective for its small systems customers, Digital Equipment Corporation provides self-paced training packages for several years that can be used by its customers on-site. To control the quality of this training, Digital is now incorporating computer managed instruction (CMI) into some of these packages. This CMI component…

An approach is described that reveals the hierarchical test structure (HTS) based on the cognitive demands of the test items, and conducts a linear trait modeling by using the HST elements as item difficulty components. This approach, referred to as the Hierarchical Latent Trait Approach (HLTA), employs an algorithm that allows all test items to…

The use of stepwise regression has been criticized for both interpretive misunderstandings and statistical aberrations. A major statistical problem with stepwise regression and other procedures that involve multiple significance tests is the inflation of the Type I error rate. General approaches to control the family-wise error rate such as the…