An examination of the effect of six types of error perturbation on fifteen clustering algorithms

An evaluation of several clustering methods was conducted. Artificial clusters which exhibited the properties of internal cohesion and external isolation were constructed. The true cluster structure was subsequently hidden by six types of error-perturbation. The results indicated that the hierarchical methods were differentially sensitive to the type of error perturbation. In addition, generally poor recovery performance was obtained when random seed points were used to start theK-means algorithms. However, two alternative starting procedures for the nonhierarchical methods produced greatly enhanced cluster recovery and were found to be robust with respect to all of the types of error examined.     

THE CLASS SPECIFIC EFFECTS OF COMPLIANCE TRAINING WITH “DO” AND “DON'T” REQUESTS: ANALOGUE ANALYSIS AND CLASSROOM APPLICATION

Two experiments are reported in which the relationship between compliance with “do” and “don't” requests was examined with developmentally disabled children. In Experiment 1, a multiple baseline design across subjects with counterbalanced treatment conditions was used to evaluate a compliance training program composed of four phases: (a) baseline, during which no consequences were delivered for compliance, (b) reinforcement for compliance with one targeted “do” request, (c) reinforcement for compliance with one targeted “don't” request, and (d) follow-up with reinforcement on a variable ratio schedule for compliance with any “do” or “don't” request. Results of probes conducted before and after training within each condition indicated that generalized compliance occurred only with requests of the same type as the target exemplar (“do” or “don't”). In Experiment 2, these results were replicated in a classroom setting. Following collection of baseline probe data on student compliance, a teacher training program was successfully implemented to increase reinforcement of compliance first with one “do” and subsequently with one “don't” request of a target student. Results of multiple baseline probes across “do” and “don't” requests indicated that the teacher generalized and maintained reinforcement of compliance with other requests of the same type and to other students, with a resulting increase in student compliance with the type of requests reinforced. The impact of treatment on both teacher and student behavior was socially validated via consumer ratings. Implications of these findings with respect to response class formation and compliance training programs are discussed.     

Personality and Daily Experience: The Promise and the Challenge

This special issue of the Journal of Personality is devoted to personality and daily experience. Through historical analysis of the daily event literature, empirical inquiry, and methodological and statistical commentary, the contributors to this issue convey both the possibilities and the problems of studying everyday life. These articles demonstrate how people's dispositions, goals, and commitments can influence daily emotional well-being and health, their inner experience, their reactions to events, and perhaps even which events they encounter. The introduction of personality to the study of daily experience holds the promise of enriching our studies of both.     

Temporal stability and predictive validity of self-assessed hand preference with first and second graders

The test-retest reliability and predictive validity of a five-item hand preference questionnaire (writing, drawing, throwing a baseball, brushing teeth, and cutting with scissors) were investigated in a sample of 80 children attending first and second grade. After 1 month, 81% of the second choices were the same as the first choices. There were interitem differences in the reliabilities of the five items. Writing and drawing hand exhibited the greatest degree of temporal stability. Writing hand was the one task which was significantly related to visual field bias as indexed by a face perception task.     

Validity and temporal stability of the chimeric face technique for studying hemispheric processing asymmetries: Data from 6-through 14-year-old children

The validity and temporal stability of the chimeric face technique as a measure of cerebral hemispheric functioning in children were investigated. The method is based upon the observation that when a subject encounters a representation of the human face, the left side (from the observer's point of view) of the face dominates his or her perception of it. This bias was shown to be present in a majority of children ranging from 6 through 14 years old, and it was stronger for right-handers than for left-handers. The 1-month temporal stability of the bias was 67%, which is comparable to that of other surface methods. As in other split-message techniques, the typical left visual field bias was more reliable than the unusual right visual field bias. The implications of these data are discussed.