Meehl's taxometric method was developed to distinguish categorical and continuous constructs. However, taxometric output can be difficult to interpret because expected results for realistic data conditions and differing procedural implementations have not been derived analytically or studied through rigorous simulations. By applying bootstrap…

Content knowledge and pedagogical practices are of particular concern to middle school science instructors teaching density. First introduced in elementary grades with the ideas of floating and sinking, density taught in middle school is geared toward understanding through the use of mathematical formulas. Using a lesson-plan study design, the…

This paper, a derivation of the multiple correlation formula for unstandardized (raw) scores, is the fourth in a series of publications. The purpose of these papers is to provide supplementary reading for students of applied statistics. The intended audience is social science graduate and advanced undergraduate students familiar with applied…

Given that the examinee knows the answer to item i if and only if he knows the answer to both item g and item h, a "conjunctive" item response model is found such that items g, h, and i all have the same mathematical form of response function. Since such items may occur in practice, it is desirable that item response models satisfy this…

This paper presents in detail a proof of the limits of the sample bivariate correlation coefficient which requires only knowledge of algebra. Notation and basic formulas of standard (z) scores, bivariate correlation formulas in unstandardized and standardized form, and algebraic inequalities are reviewed first, since they are necessary for…

Measuring object similarity using the method of free clustering is gaining in popularity. Instructions are usually simple and since no structure is imposed on the subject's selection, response bias is reduced. More importantly, measures of object similarity derived from the judges' clustering can be adequately analyzed by the methods of…

A major deficiency in classical test theory is the reliance on Pearson product-moment (PPM) correlation concepts in the definition of reliability. PPM measures are totally insensitive to first moment differences in tests which leads to the dubious assumption of essential tan-equivalence. Robinson proposed a measure of agreement that is sensitive…

Report of research on consequence of introducing an income variable into a district power equalizing formula for state aid grants for education in Vermont. (PKP)

Multivariate selection can be represented as a linear transformation in a geometric framework. In this note this approach is extended to describe the effects of selection on regression analysis and to adjust for the effects of selection using the inverse of the linear transformation. (Author/BW)

Presents a mathematical theory that can be used to define concentration places of objects within unordered classes. The application to research on the evolution of journals and subject areas is illustrated, and an online method of calculating concentration evolution is described. (1 references) (CLB)

In the family of correlation suggested by Janson and Vegilius, some coefficients are generalized squared product-moment correlations and some are not. This paper advocates a family of correlations for variables of mixed scale types in which all members are generalized squared product-moment correlations. Practical advantages are explained.…

Describes how operations on local inverted files are to be modified in order to use them in distributed information retrieval systems based on thesauri. The presented rules may be viewed as the logical approach in implementing a distributed retrieval system consisting of n local retrieval systems. (Author/MBR)

Discusses application of the "Lorenz Curve" (a graphical representation of the concentration of wealth) with the "Gini Coefficient" (an index of inequality) to measure social inequality in school finance studies. Examines the basic assumptions of these measures and suggests a minor reconception. (MCG)