The impact of the Samaritan centres on suicide in Scotland

A study of Scottish suicide rates from 1958 to 1981 showed no evidence for a preventive effect from the growth in the number of Samaritan centres.     

Suppositions, extensionality, and conditionals: a critique of the mental model theory of Johnson-Laird And Byrne (2002)

P. N. Johnson-Laird and R. M. J. Byrne proposed an influential theory of conditionals in which mental models represent logical possibilities and inferences are drawn from the extensions of possibilities that are used to represent conditionals. In this article, the authors argue that the extensional semantics underlying this theory is equivalent to that of the material, truth-functional conditional, at least for what they term "basic" conditionals, concerning arbitrary problem content. On the basis of both logical argument and psychological evidence, the authors propose that this approach is fundamentally mistaken and that conditionals must be viewed within a suppositional theory based on what philosophical logicians call the Ramsey test. The Johnson-Laird and Byrne theory is critically examined with respect to its account of basic conditionals, nonbasic conditionals, and counterfactuals.     

Dispersion-weighted kappa: An integrative framework for metric and nominal scale agreement coefficients

The rater agreement literature is complicated by the fact that it must accommodate at east two different properties of rating data: the number of raters (two versus more than two) and the rating scale level (nominal versus metric). While kappa statistics are most widely used for nominal scales, intraclass correlation coefficients have been preferred for metric scales. In this paper, we suggest a dispersion-weighted kappa framework for multiple raters that integrates some important agreement statistics by using familiar dispersion indices as weights for expressing disagreement. These weights are applied to ratings identifying cells in the traditional inter-judge contingency table. Novel agreement statistics can be obtained by applying less familiar indices of dispersion in the same wayThis revised article was published online in August 2005 with the PDF paginated correctly.     

Time trends in the adjustment of Swedish teenage girls: a 26-year comparison of 15-year-olds

The aim of this study was to investigate stability and change over 26 years in self-reported adjustment of Swedish teenage girls. Data were collected with the same questionnaire from two school-cohorts in a middle-sized Swedish community: 522 girls attending Grade 8 (approximately at age 15) in 1970, and 529 girls attending Grade 8 in 1996. The first cohort was part of the longitudinal research programme Individual Development and Adaptation (IDA). In most domains, adjustment problems were approximately as common in 1996 as in 1970, with two exceptions: more girls reported problems with self-esteem and antisocial problems in 1996. In the antisocial domain, a polarization process was indicated, with an increase also in the number of girls without adjustment problems. In the relational domains, especially peer relations, there was an increase in positive adjustment. The results are discussed in relation to earlier findings and to social changes during the period.     

The recall of missing items

In two experiments, we studied the recall of missing items. Short lists of common words were presented once and were followed immediately by a random permutation of all but one of the presented items. The task of the subject was to recall the missing item--that is, the item present in the study set but missing from the probe set. Experiment 1 replicated the high accuracy with five-item lists originally reported by Yntema and Trask (1963) and showed that the latencies were quite short (about 750 msec). Experiment 2 varied list length unpredictably and showed that accuracy was a function of both list length (four, five, or six items) and serial position. Latency was again quite short but was essentially independent of list length and serial position. It was possible to simulate most of the effects with the power set model with no free parameters (i.e., parameters that varied with the experimental manipulations). The results seemed to be more consistent with a direct access model (the power set model of TODAM; Murdock, 1995) than with a simple search or serial-scanning model.     

The Importance of Child and Adolescent Psychopathy

In commenting on the five articles in this special issue, this paper discusses (1) the concept of child and adolescent psychopathy, and whether adolescent psychopaths are qualitatively distinct from other young people; (2) the measurement of adolescent psychopathy; (3) the relationship between psychopathy and other personality dimensions; (4) childhood risk factors for psychopathy; (5) psychopathy in the context of risk factors for delinquency; and (6) the prevention and treatment of adolescent psychopathy. It is argued that the three dimensions of an arrogant, deceitful interpersonal style, deficient affective experience, and an impulsive or irresponsible behavioral style are most important at present in the definition of psychopathy. An ambitious research agenda is recommended, investigating the concept of adolescent psychopathy, developing new measures, conducting new longitudinal studies on development and risk factors, and mounting new randomized experiments on prevention and treatment.     

Intervention Groups for Adolescents With Conduct Problems: Is Aggregation Harmful or Helpful?

Past research has suggested that the aggregation of deviant peers during treatment may cause harmful effects (T. J. Dishion, J. McCord, & F. Poulin, 1999). This study compared the effectiveness of problem-solving skills training groups in which all members had conduct problems (pure group condition) with groups that consisted of adolescents with and without behavior problems (mixed group condition). Participants were 139 sixth- and seventh-graders (mean age = 12.7; 63% male; 55% White) enrolled at public middle schools. Pre-, post-, and 6-month follow-up data were collected, along with intervention process variables. Results showed that, contrary to the deviancy training hypothesis, adolescents in the pure-group condition engaged in more adaptive in-session behavior and received lower scores on the parent and teacher ratings of externalizing behavior at postintervention than those in the mixed-group condition. Mediation analyses showed that the deviancy training that occurred in the mixed-group condition accounted for their worse postintervention scores, findings consistent with the deviancy training hypothesis.     

Studies of Work: Achieving Hybrid Disciplines in IT Design and Management Studies

We explore the relationship between ethnomethodology (EM), ethnography and the needs of managers and designers in industry, considering both ethnomethodological and industrial criteria of adequacy and explicating their relationship through the concept of “audience.” We examine a range of studies in this light, with a view to their possible candidacy as hybrid studies and identify three types of application of EM studies of work: market research, design, and business improvement. Application in the first of these fields we dub “anthropological,” in that it consists in studying and reporting back on the ways of exotic people (customers). This is the application most commonly found in studies of computer supported co-operative work (CSCW). A second CSCW application, “technomethodology,” involves the introduction of EM concepts into the design process. A further application, dubbed “holding-up-a-mirror,” involves reporting back to members of a setting upon their own activities. We argue that technomethodology and holding-up-a-mirror both offer the possibility of creating hybrid disciplines. We consider the objection that improvement and design involve the introduction of value judgements that threaten the practice of EM indifference, arguing that action research can serve as a guarantee of unique adequacy (UA) by testing the researcher’s understanding as analysis in action in the setting. Furthermore, the standard of reporting required by the UA criterion contributes to the effectiveness of proposed solutions.     

Perceptual limits on low-dimensional models of Munsell reflectance spectra

Some experimental and theoretical approaches to surface-colour perception depend on approximating surface reflectance spectra by low-dimensional models. In the psychophysical experiment reported here, observers had to discriminate between patterns of Munsell surfaces and their spectral approximations under either the same or different illuminants. The approximations were produced by principal component analysis, by independent component analysis, and by artificial neural networks trained with a supervised-learning rule. In all experimental conditions, observers required, on average, at least 5 basis functions for discrimination performance to be at chance, thus placing a lower limit on the dimensionality of models of Munsell reflectance spectra.     

Minimalist surface-colour matching

Some theories of surface-colour perception assume that observers estimate the illuminant on a scene so that its effects can be discounted. A critical test of this interpretation of colour constancy is whether surface-colour matching is worse when the number of surfaces in a scene is so small that any illuminant estimate is unreliable. In the experiment reported here, observers made asymmetric colour matches between pairs of simultaneously presented Mondrian-like patterns under different daylights. The patterns had either 49 surfaces or a minimal 2 surfaces. No significant effect of number was found, suggesting that illuminant estimates are unnecessary for surface-colour matching.