A simplified proof of a theorem on the difference of the moore–penrose inverses of two positive semi–difinte matrices

Simplified proofs are given of a standard result that establishes positive semi–definiteness of the difference of the inverses of two non–singular matrices, and of the extension of this result by Milliken and Akdeniz (1977) to the difference of the Moore–Penrose inverse of two singular matrices.     

Estimating consumer acceptance limits

A methodology is developed for estimating consumer acceptance limits on a sensory attribute of a manufactured product. In concept these limits are analogous to engineering tolerances. The method is based on a generalization of Stevens' Power Law. This generalized law is expressed as a nonlinear statistical model. Instead of restricting the analysis to this particular case, a strategy is discussed for evaluating nonlinear models in general since scientific models are frequently of nonlinear form. The strategy focuses on understanding the geometrical contrasts between linear and nonlinear model estimation and assessing the bias in estimation and the departures from a Gaussian sampling distribution. Computer simulation is employed to examine the behavior of nonlinear least squares estimation. In addition to the usual Gaussian assumption, a bootstrap sample reuse procedure and a general triangular distribution are introduced for evaluating the effects of a non-Gaussian or asymmetrical error structure. Recommendations are given for further model analysis based on the simulation results. In the case of a model for which estimation bias is not a serious issue, estimating functions of the model are considered. Application of these functions to the generalization of Stevens’ Power Law leads to a means for defining and estimating consumer acceptance limits, The statistical form of the law and the model evaluation strategy are applied to consumer research data. Estimation of consumer acceptance limits is illustrated and discussed.     

Simmel at a Distance: On the History and Systematics of the Sociology of the Stranger

Abstract

Concepts made famous in “classic” works are often cited in ways that deviate from their original meaning. This often leads to cumulative confusion rather than the advancement of insight. Scrutiny of such confusions may provide fruitful points of departure for systematic codification.

In the literature which refers to Simmel's excursus on “The Stranger,” four areas of confusion can be identified

1. Simmel's conception of the stranger has periodically been equated with the concept of the “marginal man,” a very different social type;

2. Simmel's conception of the stranger has often been equated with the newly arrived outsider, another distinct type;

3. the distinction (only latent in Simmel) between strangers as individuals and stranger communities has not been articulated in later studies; and

4. the significance of the variety of ways in which Simmel used the metaphor of simultaneous closenss and remoteness has been obscured.

Clarification of the issues related to these four areas of confusion lays the basis fora typology of stranger statuses (Guest, Sojourner, Newcomer, Intruder, Inner Enemy, Marginal Man) and a related paradigm presented to assist in organizing the sociology of the stranger in a more systematic fashion.     

On the almost inconceivable misunderstandings concerning the subject of value‐free social science

A value judgment says what is good or bad, and value‐free social science simply means social science free of value judgments. Yet many sociologists regard value‐free social science as undesirable or impossible and readily make value judgments in the name of sociology. Often they display confusion about such matters as the meaning of value‐free social science, value judgments internal and external to social science, value judgments as a subject of social science, the relevance of objectivity for value‐free social science, and the difference between the human significance of social science and value‐free social science. But why so many sociologists are so value‐involved – and generally so unscientific – is sociologically understandable: The closest and most distant subjects attract the least scientific ideas. And during the past century sociologists have become increasingly close to their human subject. The debate about value‐free social science is also part of an epistemological counterrevolution of humanists (including many sociologists) against the more scientific social scientists who invaded and threatened to expropriate the human subject during the past century.     

Costs,Benefits, and Management Considerations of a Prepaid Student Dental Health Plan

Abstract

The Student Dental Health Program (SDHP) is an open panel, prepaid dental insurance plan at the University of Alabama in Birmingham. The program was developed primarily to provide optimal dental health service; however the SDHP also serves educational and research functions that are consistent with the objectives of the university. The student bodies of the Schools of Dentistry, Medicine, Nursing, and Optometry constitute the enrollee population.

Total cost rose from $18,418 in 1969–70 with 862 enrollees, to $70,930 in 1975–76 with 1,618 enrollees. During the same period the number of procedures completed increased from 2,868 to 6,796, with the average cost per procedure increasing from $6.42 to $10.44. The number of restorative services declined and preventive services increased. In 1976–77 benefits per student treated were estimated at $80 as compared to the annual fee of $48. The value of unmet needs upon entrance to the program averaged $59 per enrollee in 1974–75. By 1976–77 this figure was reduced to $26 due to implementation of an initial screening. The program is self-supporting due to a variety of cost containment measures. On balance, the program can be considered successful and beneficial to all parties concerned.     

Cost of Including Males in a University Rubella Immunization Program: A Recommendation to Change a Discriminatory Policy

Abstract

Twenty-seven University of Rochester students developed clinical manifestations of rubella during 1976–77. Twenty-five were male and had not been immunized against this disease; 18 required infirmary care costing $4,876. On the basis of data for freshman males, a cost analysis demonstrates the feasibility of changing the university policy which encourages immunization only of females to encouragement of either selective or mass immunization of all males as well. Immunization during childhood with combined MMR vaccine is least expensive and should be encouraged. In certain circumstances, selective immunization of susceptible males may be less expensive than the present selective policy, which leaves males at risk.     

Planning and health care—The approach in a reorganized NHS

From April 1974, National Health Service authorities have been merged to provide integrated and comprehensive services. The reorganization policies place considerable emphasis on the need for management and planning but planning for health services is not well developed. Ambiguous operational objectives and obscured criteria for effectiveness are not the most promising basis for planning. Nevertheless, a commendable beginning is to be made on planning comprehensively through a systematic annual review of Government health service policies and planning and programming procedures for health authorities. The outlines of the system are described and the prospects for success and further development are considered.     

THE USE OF INTERACTIVE VIDEO TO DEMONSTRATE DIFFERENTIAL APPROACHES TO MARITAL AND FAMILY THERAPY

This article outlines the development of an interactive video system designed to demonstrate differential approaches to family therapy using identical therapy situations. The primary purpose of the project is to resolve some of the confusion many novice family therapists experience while being exposed to the numerous family therapy approaches. Technical aspects of the interactive video system are also outlined.