This special issues describes multidimensional scaling (MDS), with emphasis on proximity and preference models. An introduction and six papers review statistical developments in MDS study design and scrutinize MDS research in four areas of application (consumer, social, cognitive, and vocational psychology). (SLD)

There are two basic approaches offered in current computerized transportation routing and scheduling programs: the mathematical programming approach and the intuitive optimization approach. Lists questions that an informed buyer should ask of the routing and scheduling company. (MLF)

The present study points out problems in the model, indices of familiality, and design used by Benbow, Zonderman, and Stanley in a study of precocious children and their parents. (Author/LMO)

Based on reanalyses of correlational data obtained from the University of Southern California Aptitudes Research Project, this investigation examined the extent to which two higher order factors of semantic content and symbolic content form Guilford's structure-of-intellect model reflected distinct constructs. (Author/LMO)

This study examines a score-difference model for the detection of cheating based on the difference between two scores for an examinee: one based on the appropriate scoring key and another based on an alternative, inappropriate key. It argues that the score-difference method could falsely accuse students as cheaters. (Author/JAZ)

The design, selection, and organization of instructional materials that integrate calculators are described in relation to a model based on movement and representational level. Instructional resources and advantages of the model are described. (MNS)

This study of maximum likelihood confirmatory factor analysis found effects of practical significance due to sample size, the number of indicators per factor, and the number of factors for Joreskog and Sorbom's (1981) goodness-of-fit index (GFI), GFI adjusted for degrees of freedom, and the root mean square residual. (Author/BW)

The use of quantitative techniques for research and development management in large U.S. industrial firms is reviewed, current patterns of technique familiarity and usage are described, and suggestions for the direction of project management systems are given. (MSE)

An alternative explanation is presented for the pattern of relative difficulty of arithmetical word problems to that suggested in a 1983 article. It is argued, that for many problems, much of the symbolic manipulation is accomplished externally, not internally. (MNS)

Data from the 1970 Brazilian Census are used to explore the effects of parents' investments in their children's education on the pattern of future income distribution and on the intergenerational transmission of inequality, using a simulation model. Appended are 21 references. (Author)

An example of how geometry serves as a model in the real world is outlined, with suggestions on how it might be used at the high school level. (MNS)

Rasch model equatings of multilevel achievement test data before and after the deletion of misfitting persons were compared. Rasch equatings were also compared with an equating obtained using the equipercentile method. No basis could be found in the results for choosing between the two Rasch equatings. (Author/LMO)

Mastering the basic number combinations involves discovering, labeling, and internalizing relationships, not merely drill-based memorization. Counting procedures and thinking strategies are components, and it may be that using stored procedures, rules, or principles to quickly construct combinations is cognitively more economical than relying…

The author first corrects Baroody's description of the network retrieval model for basic number facts, in which facts are stored in memory and retrieved as needed. He then indicates weaknesses in Baroody's argument. (MNS)

An empirical analysis of the relationship between science reasoning skills and the amount of information acquired during science learning as predicted by a neuromathematical model of information processing is presented. Subjects were 93 adolescents (mean age of 15.4 years old) with a IQ range of 91-142. (Author/JN)