An example of scale invariance is provided via the LISREL model that is subject only to classical normalizations and zero constraints on the parameters. Scale invariance implies that the estimated covariance matrix must satisfy certain equations, and the nature of these equations depends on the fitting function used. (TJH)

Discussion of models for library circulation data highlights a new statistical prediction model that creates a flexible regression curve. Linear graphs that result from previous models are discussed, bivariate discrete distributions are explained, and graphs that show library circulation for one year at a time are presented. (nine references) (LRW)

Across conditions, differences between population parameters defined by common factor analysis and component analysis are demonstrated. Implications for data analytic and theoretical issues related to choice of analytic model are discussed. Results suggest that principal components analysis should not be used to obtain parameters reflecting latent…

The adequacy of multidimensional trait and item parameters using multidimensional item response theory analysis was studied through simulation using different degrees of correlation between two trait dimensions and the existence of a restricted trait on the second dimension. Conditions allowing adequate recovery of trait and item parameters are…

Item response theory-based appropriateness fit indices were used to identify and remove from a validation sample (n=201) those examinees whose response patterns did not match their trait levels. Although a person-fit index had little effect on validities, a multitest index was more promising. (SLD)

A method is proposed to simultaneously estimate regression functions and subject membership in "k" latent classes or groups given a censored dependent variable for a cross-section of subjects. Maximum likelihood estimates are obtained using an EM algorithm. The method is illustrated through a consumer psychology application. (SLD)

A model for describing dynamic processes is constructed by combining the Rasch model with the concept of structurally incomplete designs. This is accomplished by mapping each item on a collection of virtual items, one of which is assumed to be presented to the respondent depending on preceding responses or feedback. (SLD)

A flexible class of stochastic mixture models is introduced and illustrated for analysis and interpretation of individual differences in recurrent choice and other types of count data. These models are derived by specifying elements of the choice process at the individual level. An easy-to-implement algorithm is presented for parameter estimation.…

Use of linear combinations of Fisher's "z" transformations as a combined test for the common correlation parameter based on "k" independent sample correlations has been previously studied. This article considers additional "z" additive properties and methods of combining independent studies when planning the number of…

A distribution theory is derived for a G. V. Glass-type (1976) estimator of effect size from studies involving paired comparisons. The possibility of combining effect sizes from studies involving a mixture of related and unrelated samples is also explored. Resulting estimates are illustrated using data from previous psychiatric research. (SLD)

Presents a unified theoretical approach to children's false-memory reports that deals with both spontaneous and implanted reports. Details false recognition and misinformation models that allow researchers to determine the impact of identity judgment, nonidentity judgment, and similarity judgment in false memory reports. (LBT)

Notes that there has been far less mathematical modeling of children's memory than of adults' memory. Explores the flaw in fuzzy-trace model, and maintains that situations in which partial verbatim information is used along with partial gist information fall outside the boundary of this type of model. Suggests refining the concepts of and…

Notes that a multitude of studies have demonstrated that misleading postevent information affects people's memories. Contents that the fuzzy-trace theory is a positive step toward understanding the malleability of memory. Discusses fuzzy-trace theory in terms of three primary areas of study: altered response format, maximized misinformation…

Notes that spontaneous false memories are a routine part of everyday memory and more common than implanted false memory. Commends the fuzzy-trace theory for the separation and explanation of these two sources of inaccuracy. Demonstrates the theory's handling of three phenomena concerning the creation and maintenance of false memories. (LBT)

Notes that fuzzy-trace theory provides a link between indices of memory performance and the theoretical processes that underlie that performance. Author argues false memories can arise because of processes that normally affect forgetting. Maintains that, to the extent that memories lose their distinctive properties, such memories may become…