A spatial analysis of the discriminability of forms in noise

Multidimensional scaling (MDS) techniques were used to study the form characteristics which transcend noise in a discrimination task. Three dimensions of random polygons were identified and were psychophysically related to quantifted form measures.     

Simultaneous vs sequential discriminations of Markov-generated stimuli

This experiment required Ss to make same-different classifications of Markov-generated histoforms that were distortions of three different prototypes. Task memory requirements were varied by presenting stimuli either simultaneously or sequentially for comparison, and the effects of shifts in memory requirements were also assessed. Classification performance in all cases was found to be superior under the simultaneous condition. Postshift performance was strictly a function of the mode of stimulus presentation following the shift, rather than the memory requirements present in the initial trials. These results, coupled with the observed relationships between performance and a measure of individual stimulus variability under the two memory conditions, strongly suggest that prototype encoding has limited relevance to performance in the same-different classification task used here.     

The variability of client,therapist and clinic in psychotherapy outcomes: A three-level hierarchical model

This article investigates the percentage of variance in psychotherapy outcomes explained by the case-mix variables for individual cases, by the therapist (therapist effects), and what additional variance is explained by the clinic with which the therapist is affiliated. While there has been substantial recent research regarding therapist effects, very little has been published regarding clinic-level effects after controlling for therapist effects. The study utilised the largest sample reported to date, using data from 28 clinics with a minimum of 2,000 cases in a clinical range of severity of symptoms with pre-post change scores on an outcome questionnaire. Only cases treated by a therapist with at least 30 cases were included. These selection criteria resulted in a case count of 156,258 clients treated by 874 therapists located at 28 clinics. After controlling for differences in case mix using diagnosis and intake score (severity of symptoms), the resulting analyses indicated that 5.21% of the variance in treatment outcome was explained by the therapist, while another 1.13% of the variance was associated with the clinic. Findings are discussed with implications for practice and policy.     

Social Value Orientations and Decisions to Take Proenvironmental Action1

This study assessed whether social value orientations influence decisions to actively support a proposal for a transportation pollution reduction program. Participants with prosocial or proself orientations were given the opportunity to send letters of support or opposition to the program director. Proself participants were more likely to send letters opposing the program, whereas prosocial participants were more likely to send letters of support. Although proself and prosocial participants reported equivalent support for the program and equivalent perceptions of the program's environmental benefits, proself participants reported higher perceptions of personal costs associated with the program. Social value orientations may lead to differences in environmental behaviors, primarily because of differences in perceptions of the personal costs incurred from engaging in these behaviors.     

Book reviews

Time's Arrow and Archimedes’ Point: New Directions for the Physics of Time Huw PRICE, 1996 New York, Oxford University Press xiii + 306 pp. SCAN 37.00 (hardcover) ISBN 0–19–510095–6

Mental Reality GALEN STRAWSON, 1994 Cambridge, MA, The MIT Press xiv + 337 pp., S37.50 (cloth), $17.50 (paper) ISBN 0–262–19352–3 (paper)

The Rule of Reason: The Philosophy of Charles Sanders Peirce JACQUELINE BRUNNING & PAUL FORSTER, Eds, 1997 Toronto, University of Toronto Press 316 pp., $80.00 (hardcover), $24.95 (paperback) ISBN 0–8020–0829–1 (cloth), ISBN 0–8020–7819–2 (paper)

Scientific Knowledge: A Sociological Approach BARRY BARNES, DAVID BLOOR & JOHN HENRY, 1996 Chicago, University of Chicago Press xvi + 230 pp., ISBN 0–226–03730–4 (cloth), 0–226–03713–2 (paperback)

The Scientific Revolution STEVEN SHAPIN, 1996 Chicago, University of Chicago Press x + 218 pp., ISBN 0–226–75020–5 (cloth), 0–226–75021–3 (paperback)