Evaluating the two-component inspection model in a simplified luggage search task

Visual inspection of X-ray images of luggage is a time-pressured task that typically shows large initial training effects, but there exists a paucity of models capable of evaluating performance and speed concurrently. In the present study, visual inspection ability during learning was modeled using Drury’s two-component inspection model (TCM; Drury, 1975) in a laboratory experiment involving 12 younger (mean age = 20.8 years) and 12 older (mean age = 60.0 years) naive participants undertaking a simplified luggage search task. Model fits and assumptions were found to be reliable and accurately reflected improvement with training for decision time, although neither search nor decision components of the model individually showed a significant effect of age. The decision component of the model showed larger improvement with training than did the search component, and stopping-time policy accurately reflected the improvements found between ages and within training levels. The TCM is a useful supplement to detection theory when speed of performance is a factor.     

Helping to improve the group stereotype: on the strategic dimension of prosocial behavior

Three studies consider a basis for intergroup helping. Specifically, they show that group members may help others to disconfirm a stereotype of their own group as mean. Study 1 shows that Scots believe they are seen as mean by the English, resent this stereotype, are motivated to refute it, and believe out-group helping is a particularly effective way of doing so. Study 2 shows that increasing the salience of the English stereotype of the Scottish as mean leads Scots to accentuate the extent to which Scots are depicted as generous. Study 3 shows that increasing the salience of the stereotype of the Scots as mean results in an increase in the help volunteered to out-group members. These results highlight how strategic concerns may result in out-group helping. In turn, they underscore the point that helping others may be a means to advance a group's interest.     

Extended similarity trees

Proximity data can be represented by an extended tree, which generalizes traditional trees by including marked segments that correspond to overlapping clusters. An extended tree is a graphical representation of the distinctive features model. A computer program (EXTREE) that constructs extended trees is described and applied to several sets of conceptual and perceptual proximity data.This research was supported in part by a National Science Foundation Pre-doctoral Fellowship to the first author.A magnetic tape containing both the EXTREE program described in the article and ADDTREE/P program for fitting additive trees can also be obtained from the above address. Requests for the program should be accompanied by a check for $25 made out to Teachers College, to cover the costs of the tape and postage.     

Computer games,self-esteem and gratification of needs in adolescents

Playing computer games has become an increasingly popular leisure time activity amongst adolescents, but concerns have been expressed over possible associated consequences. One research area has investigated reasons for playing, and two prior explanations relate it to the functional concepts of ‘electronic friendship’ and ‘self-esteem’. A questionnaire study was conducted among 120 adolescents to obtain information on a number of measures including gratification of needs and self-esteem. Results showed that playing computer games is equally popular with males and females, but males spend more time on it. Positive correlations between playing and items on the needs scales were obtained. In particular males who were heavy players scored highly on the ‘preference to friends’ need, but interestingly they were also likely to see their friends more often outside school, thus providing no support for the theory that computer games are taking the place of normal social interaction. For females there was evidence of a negative relationship between self-esteem and need gratification through playing computer games. However more adolescents spend much more time watching television than playing computer games. These results are discussed in the context of previous research.     

Nearest neighbor analysis of point processes: Applications to multidimensional scaling

A new approach for evaluating spatial statistical models based on the (random) number 0 ≤ N(i, n) ≤ n of points whose nearest neighbor is i in an ensemble of n + 1 points is discussed. The second moment of N(i, n) offers a measure of the centrality of the ensemble. The asymptotic distribution of N(i, n) and the expected degree of centrality for several spatial and nonspatial point processes is described. The use of centrality as a diagnostic statistic for multidimensional scaling is explored.     

Is menopause depressing? An investigation of three perspectives

This study examines three perspectives in the literature about menopausal depression. According to one, the physiological changes of menopause result in increased psychological distress. Another approach proposes that menopause is most depressing for women who occupy traditional female gender roles. The third asserts that menopause is not especially depressing for most women. This study empirically examines three perspectives using data from two community surveys. These analyses suggest menopausal status may not be associated with depressive symptomatology, either directly or indirectly through traditional gender roles.This research was supported in part by PHS grant numbers 5T32MH13043, 5T32MH16373, and 5T32MH15774. I appreciate the helpful comments I received from Janet Berkeley, Bruce Link, and an anonymous reviewer on earlier versions of this paper. I also am grateful to Lenore Radloff and NIMH for providing the CMHA data and to Harold Dupuy and NCHS for the HANES data.     

The sense-making approach for audience assessment of adolescents

The purpose of the research was to test the methodology used to identify how adolescents approach their nutrition concerns and questions. The methodology was based on Dervin's sense-making theory. Using a time-line interview technique, 305 adolescents 14 to 16 years of age detailed a situation involving their most important nutrition concerns. Other pertinent information was obtained. Cluster analysis was chosen as the appropriate analysis to identify groups of adolescents who responded similarly to the technique. Discriminant analysis was then used to determine which variables maximally separated the groups. Four groups were identified, two of which described action-oriented approaches to dealing with nutrition situations and differed in terms of how much outside help they wanted. The remaining two groups perceived barriers to dealing with situations and also differed in how much help they wanted. A fifth group indicated no nutrition concerns or questions. The results will be used to develop and test the effectiveness of nutrition education when it is focused on the different approaches.     

On the study of statistical intuitions

The study of intuitions and errors in judgment under uncertainty is complicated by several factors: discrepancies between acceptance and application of normative rules; effects of content on the application of rules; Socratic hints that create intuitions while testing them; demand characteristics of within-subject experiments; subjects' interpretations of experimental messages according to standard conversational rules. The positive analysis of a judgmental error in terms of heuristics may be supplemented by a negative analysis, which seeks to explain why the correct rule is not intuitively compelling. A negative analysis of non-regressive prediction is outlined.     

Complexity and colour preferences in chicks of different ages

Five- and six-day old chicks were found to prefer a complex stimulus to a simple one, whilst 2-day old ones showed no such preference; but a red stimulus, whether simple or complex, tended to be preferred at both age levels when it was paired with a non-coloured complex stimulus. Preference for complexity may be usefully viewed in any species in the context of the behavioural development of the individual.