In this paper we explore the consequences of particular stage linkage structures for the evolution of a population. We first argue the importance of mixed-sex pairs of subjects discussed a legal case, each pair seated first five feet of examples the implications of various stage connections for poulation movements. In discussing dynamic models,…

Previous studies have focused almost exclusively on the contribution of community and institutional traits to institutional success. This study indicates that the degree of institutional effectiveness in serving local educational needs may be predicated more on manipulatable institutional policies and practices affecting educational barriers than…

Marascuilo and Levin's (1970) notion of Type IV errors is extended, with respect to the interpretation of interactions in analysis of variance (ANOVA) designs. To help clarity what an interaction is and what it is not, in terms of the ANOVA model, the following points are made: (i) interactions should be thought of as linear contrasts involving…

An attempt is made to indicate why the concept of "true score" naturally leads to the belief that test validity must increase with an increase in test and/or average item reliability, and why this is correct for the classical single-factor model first introduced by Spearman. The statistical model used by Loevinger is introduced to…

We concern ourselves with the hypothesis that two variables have a perfect disattenuated correlation, hence measure the same trait except for errors of measurement. This hypothesis is equivalent to saying, within the adopted model, that true scores of two psychological tests satisfy a linear relation. Statistical tests of this hypothesis are…

Unemployment and inflation pose a trade-off problem with one being employed at the expense of the other, seriously hampering efforts to deal effectively with poverty, crime, pollution, and other domestic problems. When unemployment is high, real income is relatively low so the nation feels that it cannot afford measures to solve these questions.…

Using observational data on classroom teachers, statistical procedures are presented for studying two questions on the stability of teacher behavior over time: (1) Is the individual teacher's behavior consistent? and (2) Are individual differences among teachers consistent? Approaches and methods of previous temporal stability studies are…

A procedure for obtaining maximum likelihood trait estimates from number-correct (NC) scores for the three-parameter logistic model is presented. It produces an NC score to trait estimate conversion table. Analyses in the estimated true score metric confirm the conclusions made in the trait metric. (Author/DWH)

Focuses on the fact that an educational treatment typically involves an intervention in a growth process. By modelling this process, expected growth for various treatment groups under control conditions may be estimated. Actual growth can be compared with projected growth to estimate the value-added by the program. A simple model is developed. (RC)

Results provide a first step toward the establishment of guidelines for the experimenter who wishes to use nonmetric multidimensional scaling effectively, especially when an underlying configuration is hypothesized. (Author)

A sensitive measurement model is developed that provides transactional scale values for individual members of a group, as well as an evaluation of pairwise interactions and balances that are emergent properties of the group itself. (Author/DG)

Since all commonly used latent trait models assume a unidimensional test, the applicability of the procedure to obviously multidimensional tests is questionable. This paper presents the results of the application of latent trait, traditional, and factor analyses to a series of actual and hypothetical tests that vary in factoral complexity.…

Economic discrimination in labor markets, different pay for workers of the same ability, is analyzed in several statistical models using data for black/white and male/female earnings. The conclusion is that statistical theories are unlikely to explain labor market discrimination. (MF)