Formulas for computing the exact signed and unsigned areas between two item characteristic curves (ICCs) are presented. It is further shown that when the "c" parameters are unequal, the area between two ICCs is infinite. The significance of the exact area measures for item bias research is discussed. (Author)

Using general recognition theory, a new theory of similarity is developed, postulating that perceived similarity is determined by distributional overlap. This theory is related to existing theories of similarity. Three experiments using a total of 19 university students are presented, testing the empirical validity of the theory. (SLD)

The sampling variability and zeta-values of parameter estimates for misspecified structural equation models were examined. A Monte Carlo study was used. Results are discussed in terms of asymptotic theory and the implications for the practice of structural equation models. (SLD)

A method for detecting and interpreting disturbances of the local-independence assumption among items that share common stimulus material or other features is presented. Dichotomous and polytomous Rasch models are used to analyze structure of the learning outcome superitems. (SLD)

Two discrimination coefficients, known as "disco" and "odisco," are proposed for measuring the extent of overlap in distributions as a direct function of the variance between the arithmetic means. These coefficients are related to K. Pearson's "eta" (1905) and R. A. Fisher's "F" (1950). (SLD)

It is demonstrated, theoretically and empirically, that item sets can be selected that meet the unidimensionality assumption of most item response theory models, even though they require more than one ability for a correct response. A method for identifying such item sets for test development purposes is presented. (SLD)

The partitioning of squared Euclidean--E(sup 2)--distance between two vectors in M-dimensional space into the sum of squared lengths of vectors in mutually orthogonal subspaces is discussed. Applications to specific cluster analysis problems are provided (i.e., to design Monte Carlo studies for performance comparisons of several clustering methods…

Highlights semantic links and shows how the semantic content of hypertext links can be used for information retrieval. Discussion includes indexing and retrieval algorithms that exploit link content and node content; retrieval strategies exploiting semantic links, including conventional retrieval and constrained spreading activation techniques;…

A statistical model for citation processes is presented as a particular version of a nonhomogenous birth process. The mean value function and special transition probabilities, which can readily be calculated on the basis of known and estimated parameters, give essential information on the change of citation impact in time. (10 references) (KRN)

Pavlov denotes a family of stochastic learning strategies that achieves the mutually cooperative outcome in the iterated prisoner's dilemma against a wide variety of strategies. Although faster learners will eventually dominate a given homogeneous Pavlov population, the process must proceed through a gradual increase in the rate of learning. (JBJ)

Presents a secondary classroom investigation into mathematical modeling techniques with the graphing calculator using a match stick puzzle. Geometric models, through their corresponding area formulas, are constructed, tested, and analyzed graphically to fit specified problem conditions. (Author/MKR)

Notes advantages of using dynamic models to understand cognitive functioning: (1) they are specifically intended to represent changes that systems undergo as they evolve; (2) they can capture change in a continuous fashion; (3) they can account for development of behavior that appears orderly at times and disorderly at others, and (4) chaotic…

Recommends that analysts (1) use conventional meta-analytic statistics when testing for moderator variables; (2) perform tests between mean effect sizes; and (3) continue to perform model tests in meta-analyses for which study outcomes are already consistent if they have theoretical expectations about moderators. (RS)

A modification of the TUCKALS3 algorithm is proposed that handles three-way arrays of order I x J x K for any I. The reduced work space needed for storing data and increased execution speed make the modified algorithm very suitable for use on personal computers. (SLD)

Presents a general mathematical model of the diffusion of innovations that incorporates mass media and interpersonal influence. Suggests that policymakers can use diffusion models to evaluate the effectiveness of media versus interpersonal campaigns, make comparisons between subgroups, and evaluate the effect of a policy. (RS)