A second generation nonlinear factor analysis

Nonlinear common factor models with polynomial regression functions, including interaction terms, are fitted by simultaneously estimating the factor loadings and common factor scores, using maximum-likelihood-ratio and ordinary-least-squares methods. A Monte Carlo study gives support to a conjecture about the form of the distribution of the likelihood-ratio criterion.The research reported in this paper was partly supported by Natural Sciences and Engineering Research Grant No. A6346.     

Bayesian estimation in unrestricted factor analysis: A treatment for heywood cases

A Bayesian procedure is given for estimation in unrestricted common factor analysis. A choice of the form of the prior distribution is justified. It is shown empirically that the procedure achieves its objective of avoiding inadmissible estimates of unique variances, and is reasonably insensitive to certain variations in the shape of the prior distribution.     

The effect of orthographic structure and lexical meaning on “same-different” judgments

Pairs of high frequency English words, orthographically acceptable pseudo-words, and non-word letter strings were presented in a “same”-“different” task. The mean reaction times for “same” judgments were ordered; real words were faster than pseudo-words, and pseudo-words were faster than non-words. The RTs for the “different”, judgments showed no differences among the three types of words, except in the first two days of practice in a blocked presentation condition when the difference between the real words and non-words was marginally significant. These and other results suggest that “same” judgments are based upon a comparison process which efficiently uses higher order semantic and orthographic information in words, whereas “different” judgments are based upon comparison process which performs a self-terminating search of the graphemic information in words. The results were also discussed with reference to hierarchical models of word perception and reading.     

Choice Shifts In Political Decisionmaking: Federal Judges and Civil Liberties Cases

The purpose of this article is to investigate whether group-induced attitudinal shifts in decisionmaking take place outside the experimental laboratory and whether choice shift theory can be applied to the understanding of political behavior of actors engaged in socially relevant decisionmaking. A random sample of civil liberties decisions in Federal District Courts for the years 1963–1968 were examined. The hypothesis that there are systematic differences between single-judge and collegial court decisions was confirmed. Parties claiming a violation of constitutional rights increase the probability of successfully convincing a district judge when they are able to have their litigation heard by a three-judge court. The finding that judges are more likely to shift to a libertarian position when moving from the individual to the collegial decisionmaking condition holds when the data are examined in aggregate form as well as when the behavior of individual judges is studied under both decisionmaking settings.     

Treatment, subtype, and word type effects in dyslexic children''s response to remediation

Children diagnosed as accuracy-disabled or rate-disabled readers (Lovett, 1984a, 1986, 1987) were randomly assigned to one of three treatment conditions providing training in word recognition and decoding skills (DS), oral and written language (OWLS), or classroom survival skills (an alternative treatment control). The experimental treatment programs exerted a positive treatment effect on the word recognition performances of both groups, but treatment-specific changes in contextual reading and oral language skill were not observed. Pre- and post-treatment comparisons on an experimental word recognition task revealed a post-test advantage for DS-trained children of both subgroups. Accuracy-disabled readers demonstrated treatment-specific gains for both orthographically regular words (e.g., wade) and for exception words (e.g., broad), with their gains greater on exception words. Rate-disabled children demonstrated treatment-specific gains only for exception words, but exhibited these gains following both the DS and the OWLS treatments. Although both experimental treatment programs were associated with a positive outcome for the rate disabled subgroup, DS training was associated with relatively greater treatment gain. These data suggest that the critical variables underlying the effectiveness of the DS treatment include the specific lexical knowledge these disabled readers acquired, their greater reliance on an orthographic pattern procedure in word recognition, and/or the fact that newly acquired items were practiced to a point approximating automatization.     

Revisiting the Bay of Pigs and Vietnam Decisions 25 Years Later: How Well Has the Groupthink Hypothesis Stood the Test of Time?

Even after a quarter of a century, the groupthink hypothesis remains an influential framework for understanding the origins of group decision making fiascoes. Much of the original empirical evidence for this hypothesis was derived from a series of incisive qualitative studies of major policy fiascoes, including the ill-fated Bay of Pigs invasion and U.S. military escalation of the Vietnam War. In the 25 years since the groupthink hypothesis was first formulated, new evidence, including recently declassified documents, rich oral histories, and informative memoirs by key participants in these decisions have become available to scholars, casting new light on the decision making process behind both the Bay of Pigs and Vietnam. Much of this new evidence does not support Janis's original characterization of these processes. In particular, it suggests that dysfunctional group dynamics stemming from group members' strivings to maintain group cohesiveness were not as prominent a causal factor in the deliberation process as Janis argued. Instead, the evidence suggests that the decision making process was heavily influenced by how Presidents Kennedy and Johnson construed their options. Both Kennedy and Johnson tended to evaluate their alternatives primarily in terms of their political consequences, especially the desire to avoid what they construed as unacceptable political losses and potential damage to their reputations. Viewed in aggregate, this new evidence suggests that the groupthink hypothesis overstates the influence of small group dynamics, while understating the role political considerations played in these decisions. Thus, although both decisions may have been seriously flawed, the logic of this failure should be attributed to political psychological rather than social psychological processes.     

Exploring Nonlinear Models in Personality Assessment: Development and Preliminary Validation of a Negative Emotionality Scale

ABSTRACT In this article we discuss the applicability of several new measurement models to the construction of personality scales, and we contrast these models with more traditional approaches in common usage, such as the principal factor analysis model. Our goal is to illustrate how nonlinear item-response models can be profitably used in personality research. We describe the development of a 30-item Negative Emotionality scale that was constructed using nonlinear factor analysis and item-response theory. We also show how traditional (linear) factor analysis can produce misleading results when it is applied to personality items with dichotomous response formats (e.g., true/false, agree/disagree). No formal training in modern measurement theory is assumed of the reader as we describe the nonlinear models that are used in this study in nontechnical language with a minimum of mathematics.     

Infantile handling and the facilitation of discrimination and reversal learning

One group of rats was removed from their home cage and received daily handling from Days 3-21, while the control group of litter mates remained in the cage and did not receive any treatment. On Day 22 all rats were weaned and they were housed in individual cages until they were 60 days old. After two pretraining days, subjects were given daily blocks of one free and three forced trials in the T-maze and were rewarded with food after making the correct response. Following 20 days of training and testing on black-white discrimination, subjects were given 10 days of reversal training with four daily trials. Results indicate that the handled animals showed faster running and a greater number of correct choices than the control rats during both the acquisition and reversal learning phases of the experiment.     

Outpatient groups for chronic psychiatric patients

Long-term support groups have been utilized at the University of Alberta Hospitals since 1977 in order to meet the needs of chronic psychiatric patients who are unwilling or unable to commit to insight-oriented therapy. These groups meet once weekly for one hour and are intended to be drop-in groups, which patients can use regularly or only while in crisis. It is hypothesized that the institution or style of therapy practiced at an institution, rather than the specific therapists, provides a source of stability and support to these patients. Our experience suggests these groups are beneficial and cost-efficient, but research is necesssary to evaluate them to determine components of therapeutic effectiveness.Linda McAuley, M.A., was a staff therapist at the Psychiatric Walk-in Clinic and is currently in private practice.An earlier version of this paper was presented at a meeting of the Canadian Group Psychotherapy Association in Banff, Alberta, October, 1987.