Assessing the stability of principal components using regression

This paper presents an analysis, based on simulation, of the stability of principal components. Stability is measured by the expectation of the absolute inner product of the sample principal component with the corresponding population component. A multiple regression model to predict stability is devised, calibrated, and tested using simulated Normal data. Results show that the model can provide useful predictions of individual principal component stability when working with correlation matrices. Further, the predictive validity of the model is tested against data simulated from three non-Normal distributions. The model predicted very well even when the data departed from normality, thus giving robustness to the proposed measure. Used in conjunction with other existing rules this measure will help the user in determining interpretability of principal components.The authors would like to thank the four anonymous reviewers and the two editors for their valuable comments. Atanu R. Sinha gratefully acknowledges the research support received from the Marketing Studies Center, AGSM, UCLA. Send requests for reprints to Atanu R. Sinha, B418 Gold Hall, 110 Westwood Plaza, Los Angeles, CA 90095.     

Cultural attitudes: in contexts of argumentation and explanation

Traditionally, attitudes are supposed to predict behavior. However, due to their poor performance, we are sometimes advised to abandon the notion. The present study attempts to preserve the concept but takes attitudes to be evaluative goals accomplished through interactional, especially argumentative and explanatory activities. The paper uses reasoned-discourse analysis and demonstrates the attainment of positive attitudes towards the Dutch by expatriate Chinese intellectuals in the Netherlands by attending to a variety of argumentative and explanatory strategies in their interview talk. Results suggest that there is good empirical reason to believe that attitudes are accomplishments of communicating actors' rhetorical contextualizations.     

Psychological and educational characteristics of instruction for people with severe disabilities: Interacting systems of responding

This paper presents a behavioral model which proposes that operants are organized and regulated into systems of responding. Multi-operant theory proposes that operants are organized into response systems that interact to adapt behavior to the complexities of the environment. The operant is the interaction between behavior and the environment which includes the conditions under which responses may occur, the class of behavior that is likely to be effective in producing outcomes, and the antecedent conditions that define the context of behavior. A central feature of this theory is that operants within a repertoire are organized into regulated systems of responding. The mechanisms of regulation are themselves operants that are learned and controlled by processes that are the same as those that govern more overt behavior. Operants stand in relationship to each other in coordinated response systems with some operants directly affecting and organizing the performance of other operants. An important implication of the systemic nature of behavioral repertoires is that bringing some aspect of a behavior class under control of new variables may demonstrate a spread throughout the entire operant system depending on past histories linking the classes.deceased     

Comparative evaluation of two superior stopping rules for hierarchical cluster analysis

A split-sample replication stopping rule for hierarchical cluster analysis is compared with the internal criterion previously found superior by Milligan and Cooper (1985) in their comparison of 30 different procedures. The number and extent of overlap of the latent population distributions was systematically varied in the present evaluation of stopping-rule validity. Equal and unequal population base rates were also considered. Both stopping rules correctly identified the actual number of populations when there was essentially no overlap and clusters occupied visually distinct regions of the measurement space. The replication criterion, which is evaluated by clustering of cluster means from preliminary analyses that are accomplished on random partitions of an original data set, was superior as the degree of overlap in population distributions increased. Neither method performed adequately when overlap obliterated visually discernible density nodes.This research was supported in part by NIMH grant 5R01 MH 32457 14.     

Spectral and pattern response in the rabbit retina.

The advantages of presenting sensory data in terms of stimulus variables are stressed. Spectral sensitivity plots of local electroretinograms and ganglion cell discharges from the dark-adapted rabbit retina illustrate the utility of using this kind of procedure. Spectral data agreed with the literature demonstrating two cone and one rod process in this animal. The spectral sensitivities of both the local electroretinogram and ganglion cell spikes were closely similar. Data pertaining to pattern vision may also be subjected to the same type of analysis and described in terms of stimulus variables.     

The judgment-choice discrepancy: Noncompatibility or restructuring?

The study examines the relative merits of a noncompatibility and a restructuring explanation of the recurrent empirical finding that a prominent attribute looms larger in choices than in judgments. Pairs of equally attractive options were presented to 72 undergraduates who were assigned to six conditions in which they performed (1) only preference judgments or choices, (2) preference judgments or choices preceded by judgments of attractiveness of attribute levels, or (3) preference judgments or choices accompanied by think-aloud reports. The results replicated the prominence effect for choices, but a prominence effect was also found for preference judgments. In accordance with the restructuring explanation, the think-aloud protocols indicated that options were more often restructured in choices than in preference judgments. However, restructuring could not explain the prominence effect observed for preference judgments. A modified compatibility hypothesis is offered as an alternative explanation.     

Towards reflexive practice: Engaging participants as co-researchers or co-analysts in psychological inquiry

This paper considers some of the implications of reflexivity for the practice of psychological research. After a brief consideration of the theoretical background to a concern with reflexivity, the paper goes on to examine how various researchers have attempted to incorporate components of reflexivity in their research practice. While a group of sociologists of science have operationalized reflexivity by self-conscious concern for their own role in the construction of social—scientific knowledge, new paradigm co-operative inquirers interpret a need for reflexivity by including their participants as fully self-reflexive co-researchers. Mulkay's suggestion for a dialogic analytical exchange with one's participants is also considered. The second half of the paper illustrates an attempt at reflexive practice in the authors' own research. This was a project concerned with identity change during the transition to motherhood, and aimed to allow the women a strong hand in helping to shape the project's direction. Preliminary analysis of a woman's data was taken back to her for her comments, and her reflections on the data were incorporated in the final case study. A detailed example of the investigator and participant's discussion of a piece of data is provided.     

Internet resources in applied behavior analysis

Internet communication is becoming an important tool for both academic and clinical areas in psychology and behavior analysis. The Internet, a confederation of thousands of computer systems covering the entire globe (Plaud, 1996b), can significantly enhance behavior analysis in at least three major areas: (a) information exchange and communication among behavior analysts through list servers, (b) dissemination of empirical data and commentary through on-line journals and information servers, and (c) promotion of programs and services in behavior analysis. This commentary provides specific examples in each of these areas and addresses the basics of connecting to the Internet.