A jackknife test of homogeneity of variance with paired replicates data

A nonparametric test of dispersion with paired replicates data is described which involves jackknifing logarithmic transformations of the ratio of variance estimates for the pre- and post-treatment populations. Results from a Monte Carlo simulation show that the test performs well underH _o and has good power properties. Examples are given of applying the procedure on psychiatric data.A referee called our attention to valuable references which related to our work, and he suggested the inclusion of competing jackknife procedures into our studies.     

Foreign Investments in Southern Africa

“If one believes in the Prince of Peace one must stop committing crimes in the name of the Prince of Peace. The Christian Church still rules this world, it still has the power to change the structure of South Africa.” James Baldwin in his address to the Fourth Assembly of the World Council of Churches, Uppsala, 1968.     

A stimulus-compounding assay of conditioned inhibition and excitation

Rats were trained in an operant discrimination involving two panel lights, A and B. Group CI (Conditioned Inhibition) was trained to lever press in the presence of A (S+), and not in the presence of the compound AB (S?). The opposite contingencies held in Group CE (Conditioned Excitation). Response rates were higher in Group CE than in Group CI, especially to the positive stimulus. However, the groups acquired the discrimination at comparable rates. In a separate phase of the experiment, a tone (C) was separately trained in the absence of the lights to control responding. All seven possible combinations of A, B, and C were then presented randomly during extinction. The inhibitory effect of B on C in Group CI was comparable in magnitude to the excitatory effect of B on C in Group CE. B's effect on C was not altered by the presence or absence of A, regardless of whether A was inhibitory or excitatory. The symmetry between CI and CE revealed by the stimulus-compounding test may be partly artifactual.     

MAINTENANCE OF FOREIGN LANGUAGE VOCABULARY AND THE SPACING EFFECT

Abstract— In a 9-year longitudinal investigation, 4 subjects learned and relearned 300 English-foreign language word pairs. Either 13 or 26 relearning sessions were administered at intervals of 14, 28, or 56 days. Retention was tested for 1, 2, 3, or 5 years after training terminated. The longer intersession intervals slowed down acquisition slightly, but this disadvantage during training was offset by substantially higher retention. Thirteen retraining sessions spaced at 56 days yielded retention comparable to 26 sessions spaced at 14 days. The retention benefit due to additional sessions was independent of the benefit due to spacing, and both variables facilitated retention of words regardless of difficulty level and of the consistency of retrieval during training. The benefits of spaced retrieval practice to long-term maintenance of access to academic knowledge areas are discussed.     

The use of a consultation team to network families with other helping systems

Families, therapists, and other service providers often find themselves uncooperative and at cross purposes when working toward solutions to family problems. Sometimes each professional is involved in one small piece of the problem and may never have encountered other providers and all family members. This paper describes a family-agencies-team consultation model intended to address the above issues. The model uses a consultation team to facilitate better understanding of family needs, helping agency roles, and service provider constraints. The approach has been successful in creating dialogue, generating a wide range of goals, engendering cooperation, empowering families, and affirming agency participation.In addition to the authors, the consultation team included staff members at the Pitt County Mental Health Center working with client families and other agencies in Pitt County, North Carolina.     

Acalculia: An historical review of localization

This article reviews the brain localization of calculation disorders (acalculia) beginning with Gall's claim in the early 19th century for a "center" of calculation. A renewed interest in the subject arose around the time of Henschen during the first quarter of the 20th century. A summary of the cases of acalculia since Henschen leads to the conclusion that regardless of the functional modular nature of calculation ability, there is neither a localized region nor a specific hemisphere uniquely underlying the disorder.     

Judgments of men's and women's feelings during hypothetical social interactions

We studied college students' perceptions of how good/bad and how powerful/powerless men and women feel during hypothetical social interactions. Stimuli were constructed by combining each of 16 behaviors that fell into four categories (negative, low power, sexual, and help) with each of four dyads (male-male, male-female, female-male, female-female). Subjects made judgments about the likelihood of each behavior occurring, and about how actors and recipients felt when engaging in each of 16 behaviors. Three themes pervaded the results. First, subjects perceived men to feel more powerful than women whether behaving as actors or recipients—especially during interactions with women. Second, subjects perceived behaviors to be more likely, and actors and recipients to feel better and more powerful when the interaction pattern was consistent with gender role norms. Third, subjects perceived recipients' affective responses as being more polarized in opposite-sex than in same-sex dyads. Results from this research show that subjects' perceptions about feelings are largely consistent with the literature on social interaction and sex role stereotypes, and are similar for male and female subjects. In addition, our results provide a rich set of hypotheses concerning whether perceptions of feelings reflect actual feelings and are related to interaction participants' actual behavior.