Gennclus: New models for general nonhierarchical clustering analysis

A general class of nonhierarchical clustering models and associated algorithms for fitting them are presented. These (metric) clustering models generalize the Shepard-Arabie Additive Clusters model in allowing for: (1). either overlapping or nonoverlapping clusters; (2). either symmetric (one-way clustering) or nonsymmetric (two-way clustering) proximities (input data); and, (3). either symmetric or diagonal weights. The GENNCLUS algorithms utilize alternating least-squares methods combining ordinary and constrained least-squares, nonlinear constrained mathematical programming, and combinatorial optimization techniques in estimating model parameters. In addition to developing the mathematical bases of these models, a comprehensive set of Monte Carlo simulations of the different models is reported. Two applications concerning brand-switching data and celebrity-brand proximities are discussed. Finally, extensions to three-way models, nonmetric analyses, and other model specifications are provided.Wayne S. DeSarbo is a Member of Technical Staff in the Mathematics and Statistics Research Center at Bell Laboratories in Murray Hill, N.J. I wish to thank R. Gnanadesikan, J. D. Carroll, and P. Arabie for their comments on a previous draft of this paper. I also wish to acknowledge the computer assistance provided by Linda Clark. Finally, I wish to thank the reviewers and editor for their very complete reviews and comments.     

The simultaneous and independent measurement of penile circumference and length

It has been recently shown that in the early stages of erection, the human penis undergoes a substantial length change that is not detected using circumferential measurement devices. The present report introduces a relatively simple device that can assess changes in both length and circumference. The device promises to provide a low-cost alternative to the precision and sensitivity associated with plethysmography.     

Duration discrimination in a series of rhythmic events

Duration discrimination of the last of a series of four clicks was investigated. Examination of psychophysical functions from eight subjects revealed evidence for a Weber’s law model relating discrimination to base interclick interval. Also, the point of subjective equality was seen to change reliably as a function of base rate.     

Selective perception of events

Two hundred and twelve subjects were given one of two interpretive sets prior to viewing an event. Following observation, the first interpretation was discredited, and subjects were asked to interpret the event they had seen under the contrasting set. Some subjects were only provided with the alternate interpretation, while others were also given an opportunity to view the event a second time. Both the perceptual segmentation and the subjects' impressions of the participants in the event were assessed. Results disclosed that (1) the two sets produced both differing perceptual organization and differing impressions of the participants; (2) reversing the sets produced a reversal of the impressions of the participants only when accompanied by a second viewing; and (3) the reversal of the impressions was accompanied by a shift in the perceptual organization of the event. It was concluded that observers may differ in their initial perception of an event as the result of differences in prior expectations, and that the resulting biased sample of information they acquire may limit their retrospective reinterpretation of the event.     

Psychoanalysis and systems in family therapy

This paper describes three frames of reference for understanding family function. The three frames are (1) The Life-cycle of the Family, (2) The Intergenerational, Historical Aspects of the Family, (3) The Interactional Structure of the Family. It is suggested that these three frames can provide a detailed formulation of family functioning and disturbance in order to plan rational foci, strategies, techniques and aims of family therapy.     

Children in family therapy

The distinctive skills of child psychotherapy can be utilized in the development of a form of conjoint family therapy especially applicable to the field of child psychiatry. It is suggested that the engagement of children in the process particularly enhances the specific characteristics and potentialities of this form of treatment.     

Measuring circadian cycles: A simple temperature recording preparation

While measurement of temperature as an index of circadian rhythmicity is not a difficult task with infrahuman subjects, long-term monitoring of deep body temperature with human subjects poses numerous measurement and safety problems. A preparation is described that is highly accurate, inexpensive, chronic, comfortable, and eliminates safety problems associated with more traditional methods of temperature measurement.