An incomplete data approach to the analysis of covariance structures

In this paper, linear structural equation models with latent variables are considered. It is shown how many common models arise from incomplete observation of a relatively simple system. Subclasses of models with conditional independence interpretations are also discussed. Using an incomplete data point of view, the relationships between the incomplete and complete data likelihoods, assuming normality, are highlighted. For computing maximum likelihood estimates, the EM algorithm and alternatives are surveyed. For the alternative algorithms, simplified expressions for computing function values and derivatives are given. Likelihood ratio tests based on complete and incomplete data are related, and an example on using their relationship to improve the fit of a model is given.This research forms part of the author's doctoral thesis and was supported by a Commonwealth Postgraduate Research Award. The author also wishes to acknowledge the support of CSIRO during the preparation of this paper and the referees' comments which led to substantial improvements.     

Measuring clinical pain

There are two goals in attempts to measure, the intention to describe and the intention to compare. These two functions work hand in hand and are brought to fruition in psychological and educational testing only by psychometrics that can produce person-free item calibrations and item-free person measures. The only such psychometrics that currently exist is that based on George Rasch's work. One of the consequences of using the tools Rasch left us is the Pain Scale, a rating scale that asks the person in pain to compare the intensityof his/her own pain with that he/she imagines is described by some 25 adjectives. Analyses of the responses of 53 people with chronic lower back pain to the Pain Scale using the Rasch partial-credit latent-trait model show that they were very much in agreement about the amount of hurt implied by each of the adjectives. An examination of person fit to the partial-credit model gave no hint of a response set in the data but two people did differ very much from their peers in their operational definitions of back pain and were studied separately. The evidence from these two people suggested that they either could not understand the task before them or could not get enough perspective on their pain to describe its intensity.I would like to thank Benjamin Wright and Geoff Masters for their help with this research. Drs. David J. Smith and James B. Boscardin were the first to bring my attention to the problem of measuring pain and were generous in their financial support of this work.     

Psychometric latent response models

In this paper, some psychometric models will be presented that belong to the larger class oflatent response models (LRMs). First, LRMs are introduced by means of an application in the field ofcomponential item response theory (Embretson, 1980, 1984). Second, a general definition of LRMs (not specific for the psychometric subclass) is given. Third, some more psychometric LRMs, and examples of how they can be applied, are presented. Fourth, a method for obtaining maximum likelihood (ML) and some maximum a posteriori (MAP) estimates of the parameters of LRMs is presented. This method is then applied to theconjunctive Rasch model. Fifth and last, an application of the conjunctive Rasch model is presented. This model was applied to responses to typical verbal ability items (open synonym items).This paper presents theoretical and empirical results of a research project supported by the Research Council [Onderzoeksraad] of the University of Leuven (grant number 89-9) to Paul De Boeck and Luc Delbeke.     

Economics, ecologics, and mechanics: The dynamics of responding under conditions of varying motivation

The mechanics of behavior developed by Killeen (1994) is extended to deal with deprivation and satiation and with recovery of arousal at the beginning of sessions. The extended theory is validated against satiation curves and within-session changes in response rates. Anomalies, such as (a) the positive correlation between magnitude of an incentive and response rates in some contexts and a negative correlation in other contexts and (b) the greater prominence of incentive effects when magnitude is varied within the session rather than between sessions, are explained in terms of the basic interplay of drive and incentive motivation. The models are applied to data from closed economies in which changes of satiation levels play a key role in determining the changes in behavior. Relaxation of various assumptions leads to closed-form models for response rates and demand functions in these contexts, ones that show reasonable accord with the data and reinforce arguments for unit price as a controlling variable. The central role of deprivation level in this treatment distinguishes it from economic models. It is argued that traditional experiments should be redesigned to reveal basic principles, that ecologic experiments should be redesigned to test the applicability of those principles in more natural contexts, and that behavioral economics should consist of the applications of these principles to economic contexts, not the adoption of economic models as alternatives to behavioral analysis.     

ECOLOGY AND ESCHATOLOGY: SCIENCE AND THEOLOGICAL MODELING

Abstract. The possibility of in-breakings of God in science is discussed. A realist philosophy of science is used as a framework in which new paradigms are seen as providing ever better approximations to the true underlying structure of nature, which will be revealed in the eschaton. It is argued that ecology–the study of the earth as a whole–cannot be treated as a natural science because there can be no paradigms for understanding the earth as a whole. Instead technology is used as a means for interacting with God through nature.     

A general model for preferential and triadic choice in terms of centralF distribution functions

A model for preferential and triadic choice is derived in terms of weighted sums of centralF distribution functions. This model is a probabilistic generalization of Coombs' (1964) unfolding model and special cases, such as the model of Zinnes and Griggs (1974), can be derived easily from it. This new form extends previous work by Mullen and Ennis (1991) and provides more insight into the same problem that they discussed.     

Applying developmental previewing to the principles of family therapy

This paper discusses the application of principles of infant psychiatry to the diagnosis and treatment of multigenerational family conflict. Using a technique referred to as previewing, the therapist can focus on the interpersonal meaning that the infant's development precipitates in the family and determine how the parents' relationships with the infant replicate their relationships with their own families of origin. The therapist may then use these insights for overcoming conflict and for acclimating parents to new developmental skills in an optimal manner. Specific suggestions for how parents may promote more adaptive patterns of interaction with the infant using previewing are offered.     

Thurstonian modeling of ranking data via mean and covariance structure analysis

Although Thurstonian models provide an attractive representation of choice behavior, they have not been extensively used in ranking applications since only recently efficient estimation methods for these models have been developed. These, however, require the use of special-purpose estimation programs, which limits their applicability. Here we introduce a formulation of Thurstonian ranking models that turns an idiosyncratic estimation problem into an estimation problem involving mean and covariance structures with dichotomous indicators. Well-known standard solutions for the latter can be readily applied to this specific problem, and as a result any Thurstonian model for ranking data can be fitted using existing general purpose software for mean and covariance structure analysis. Although the most popular programs for covariance structure analysis (e.g., LISREL and EQS) cannot be presently used to estimate Thurstonian ranking models, other programs such as MECOSA already exist that can be straightforwardly used to estimate these models.This paper is based on the author's doctoral dissertation. Ulf Böckenholt was my advisor. The author is indebted to Ulf Böckenholt for his comments on a previous version of this paper and to Gerhard Arminger for his extensive support on the use of MECOSA. The final stages of this research took place while the author was at the Department of Statistics and Econometrics, Universidad Carlos III de Madrid. Conversations with my colleague there, Adolfo Hernández, helped to greatly improve this paper.     

Situation Models: The Mental Leap Into Imagined Worlds

Situation models are mental representations of the state of affairs described in a text rather than of the text itself. Much of the research on situation models in narrative comprehension suggests that comprehenders behave as though they are in the narrated situation rather than outside of it. This article reviews some of this evidence and provides an outlook on future developments.     

Introduction: Neuropsychological Assessment Après Luria

Neuropsychological assessment since Alexander R. Luria's death in 1977 has demonstrated increased sophistication and advancement, and a number of models or approaches to neuropsychological assessment are available worldwide today. This article reviews, in the context of this special issue, Luria's influence on the further development of neuropsychological assessment approaches and methods. Contemporary approaches are summarized and contrasted, and a discussion of neo-Lurian adaptations and extensions of his neuropsychological model is presented. Brief comments about the succeeding articles in this issue help to demonstrate the wide influence sustained by Luria's ideas in various regions of the world.