Testing hypotheses about the common mean of normal distributions

An overview of hypothesis testing for the common mean of independent normal distributions is given. The case of two populations is studied in detail. A number of different types of tests are studied. Among them are a test based on the maximum of the two available t-tests, Fisher's combined test, a test based on Graybill–Deal's estimator, an approximation to the likelihood ratio test, and some tests derived using some Bayesian considerations for improper priors along with intuitive considerations. Based on some theoretical findings and mostly based on a Monte Carlo study the conclusions are that for the most part the Bayes-intuitive type tests are superior and can be recommended. When the variances of the populations are close the approximate likelihood ratio test does best.     

Adjusting for bias in randomized cluster trials

The randomized cluster design is typical in studies where the unit of randomization is a cluster of individuals rather than the individual. Evaluating various intervention strategies across medical care providers at either an institutional level or at a physician group practice level fits the randomized cluster model. Clearly, the analytical approach to such studies must take the unit of randomization and accompanying intraclass correlation into consideration. We review alternative methods to the typical Pearson's chi-square analysis and illustrate these alternatives. We have written and tested a Fortran program that produces the statistics outlined in this paper. The program, in an executable format is available from the author on request.     

Marital violence: An integrated systems approach

A review of current issues and approaches to the problem of marital violence is presented. In order to understand volatile relationships, these attachments are discussed within the context of the normal progression of events in the formation and development of a marriage. A systems model that integrates current conceptual thinking is presented. The article concludes with a paradigm for therapeutic decision-making and strategies that flow from the integrated systems model.     

Frustrated Fertility: Infertility and Psychological Distress Among Women

Using a random sample of 580 Midwestern women, we test the hypothesis that women who have experienced infertility report higher psychological distress. Approximately one third of our sample reports having experienced infertility sometime in their lives, although the majority of the infertile now have biological children. Drawing hypotheses from identity and stress theories, we examine whether roles or resources condition the effects of infertility or whether its effects are limited to childless women. Infertility combined with involuntary childlessness (including biological and social) is associated with significantly greater distress. For women in this category, the risk of distress is substantial.