On the partitioning of squared Euclidean distance and its applications in cluster analysis

The partitioning of squared Eucliean distance between two vectors in M-dimensional space into the sum of squared lengths of vectors in mutually orthogonal subspaces is discussed and applications given to specific cluster analysis problems. Examples of how the partitioning idea can be used to help describe and interpret derived clusters, derive similarity measures for use in cluster analysis, and to design Monte Carlo studies with carefully specified types and magnitudes of differences between the underlying population mean vectors are presented. Most of the example applications presented in this paper involve the clustering of longitudinal data, but their use in cluster analysis need not be limited to this arena.     

Sex differences in the structure of intelligence: A confirmatory factor analysis

The LISREL model of Jöreskog and Sörbom was used to perform a comparative factor analysis on intelligence data from four sex by generation groups. The covariance matrices for 10 psychometric ability measures were used to isolate Spatial and Verbal Intelligence factors. Results from a series of factor analysis models indicated substantial invariance in the factor pattern and factor covariance matrices, although the hypothesis of complete invariance in factor pattern was rejected. The groups did differ in observed and unique variances. The results were basically consistent with the hypothesis that males and females have similar intellectual structure, which would have been obscured had standardized factor analysis been employed. There were also sex and generation differences in the Spatial and Verbal factor means.     

Exteroceptive context in tasteaversion conditioning and extinction: odour, cage, and bottle stimuli

Five experiments investigated the extent to which the exteroceptive context, present on a saccharin aversion conditioning trial with rats, controlled the resulting aversion on one-bottle extinction tests and subsequent preference tests. The presence or absence of the specific odour which had been present on the conditioning trial was found not to influence saccharin intake on extinction tests, whereas the presence of the particular compartment in which, and the bottle from which, the saccharin had been consumed greatly suppressed saccharin intake as compared to the absence of these elements. Preference tests, performed in the respective conditioning contexts, showed extinction to be specific to the compartment + bottle context: groups that had extinguished their saccharin aversion in a context different from the conditioning context, retained their aversion in the conditioning context. No such specificity was found for the odour context. However, in the absence of the taste stimulus during the extinction phase, the odour that had been present on the conditioning trial did control the amount of water consumed, whereas the compartment+bottle context did not. Moreover, on preference tests, groups that had consumed water during extinction in the presence of the odour context, evidenced a lesser saccharin aversion than groups not exposed to the odour. The results are interpreted as demonstrating that rats learn about taste, odour, cage and bottle stimuli on a taste-aversion conditioning trial, and that taste and bottle stimuli seem to be the most salient.     

Problems of Communication in Inter-American Programs

We use our own culture as a basis for interpreting the behavior of others and their failure to make responses we expect. Sometimes the nature of the problem soon becomes apparent but in other situations the causes may remain invisible. Certain problems may relate particularly to two characteristics of Latin American countries: the absence of our “puritanical” tradition and the presence of an elaborate system of “extended family” relationships we do not have. Counseling and guidance specialists may be affected by (1) the fact that teacher-pupil relationships include less of the “surrogate parent” element than in the U.S.; (2) difficulties students encounter in moving from one career choice to another; (3) the power of student organizations; and (4) an expectation that the specialist will provide definitive advice rather than help the student solve his own problems. Many Latin American students have negative images of North Americans; they “remember” history and tend to think in longer time blocks than are customary with us. A 10-year aid program, for example, may be seen as a short-range venture.     

Layoffs,self-esteem,and survivor guilt: Motivational,affective, and attitudinal consequences

The present study explored the effect of layoffs on the subsequent productivity of “survivors”. All participants performed a proofreading task either after witnessing the dismissal of a co-worker (Layoff condition) or not (No-Layoff condition). Consistent with equity theory, the quantity of workers' performance was greater in the Layoff than in the No-Layoff condition. A Worker Self-Esteem × Layoff interaction effect revealed that the Layoff effect was entirely attributable to the low, rather than the medium or high, self-esteem participants. Additional analyses revealed that the layoff caused participants to (1) experience increased feelings of remorse and (2) develop more negative attitudes toward their co-worker, both of which are also consistent with equity theory. Practical and theoretical implications are discussed.     

Game Theory and Decentralisation

Whereas many environmentalists have traditionally argued in favour of small-scale, decentralised communities as a solution to the environmental crises which we appear to face, some environmental political theorists have recently argued against decentralisation. In this article I first show that game theory seems, at first glance, to support the insistence by statists that decentralisation is highly impracticable. But, second, I then attempt to demonstrate that, on closer inspection, game theory actually provides considerable support for the decentralist case.