Comparative evaluation of two superior stopping rules for hierarchical cluster analysis

A split-sample replication stopping rule for hierarchical cluster analysis is compared with the internal criterion previously found superior by Milligan and Cooper (1985) in their comparison of 30 different procedures. The number and extent of overlap of the latent population distributions was systematically varied in the present evaluation of stopping-rule validity. Equal and unequal population base rates were also considered. Both stopping rules correctly identified the actual number of populations when there was essentially no overlap and clusters occupied visually distinct regions of the measurement space. The replication criterion, which is evaluated by clustering of cluster means from preliminary analyses that are accomplished on random partitions of an original data set, was superior as the degree of overlap in population distributions increased. Neither method performed adequately when overlap obliterated visually discernible density nodes.This research was supported in part by NIMH grant 5R01 MH 32457 14.     

Specificity of Dating Aggression and Its Justification Among High-Risk Adolescents

Ninety-five high-risk adolescents were studied to determine whether their dating aggression and its justification as a response to interpersonal problems were specific to the current partner, general to dating relationships, or part of a global age-mate (same-sex peers and opposite-sex dating partners) aggression problem. Approximately one-third of males and two-thirds of females reported physical aggression against their current dating partner. Males' aggression (and its justification) toward their current dating partner was part of a generalized pattern of dating aggression, whereas for females, physical aggression against a current dating partner (and its justification) was partner-specific and unrelated to aggression in other relationships. Findings are discussed with regard to intervention and future research on adolescent dating aggression.     

Concurrent validity of Holland's theory for non-college-degreed black women

This study, using the Vocational Preference Inventory (VPI) and the Self-Directed Search (SDS), explored the concurrent validity of Holland's theory for employed non-college-degreed black women. The VPI and the SDS were administered to 102 black women workers in occupational environments consistent with Holland's six vocational environments. The results revealed that four scales of the VPI and four scales of the SDS successfully differentiated the occupational groups consistent with Holland's theoretical notions. In general, the findings lend some support to the concurrent validity of Holland's theory for employed non-college-degreed black women.     

The relationship of sex and sex role to trait and situationally specific anxiety types

While considerable research has investigated the relationship of sex and/or sex role to general or trait anxiety, little is known about their relationship to more specific anxiety types. Based on the postulate that sex and sex-role differences may depend on the extent to which an anxiety-producing situation represents a sex-stereotypic domain, the present study compared their relationships to four measures of anxiety: Math anxiety, test anxiety, and two measures of trait anxiety. Subjects were 180 undergraduate students enrolled in introductory psychology courses. Although females reported higher levels of anxiety on all four scales than did males, a discriminant function analysis indicated that math anxiety was the strongest contributor to the separation of the sexes. Significant score differences as a function of sex role were found using the STAI A-Trait scale, and a significant sex × sex-role interaction was found for scores on the S-R Inventory of Anxiousness. Feminine-typed males and undifferentiated females reported highest anxiety levels in comparison to same-sex individuals. Implications for the understanding and treatment of both general and situationally specific anxiety are discussed.     

The relationship of mathematics self-efficacy expectations to the selection of science-based college majors

The major purpose of the present study was to investigate the relationship of mathematics self-efficacy expectations to the selection of science-based majors in college males and females. Based on results obtained from a pilot sample of college students, an instrument assessing mathematics self-efficacy expectations was developed. The items used in the mathematics self-efficacy scale included everyday math tasks, math problems, and math-based college courses. Subjects, 153 female and 109 male undergraduates, completed the mathematics self-efficacy scale, the Bem Sex Role Inventory, an adapted version of the Fennema-Sherman Mathematics Attitudes Scales, and a questionnaire concerning their college major choices. Results indicated that mathematics self-efficacy expectations were significantly related to the extent to which students selected science-based college majors, thus supporting the postulated role of cognitive mediational factors in educational and career choice behavior. In addition, the math-related self-efficacy expectations of college males were significantly stronger than were those of college females. Implications of the findings for the process of educational and career decision-making are discussed.     

The predictive efficiency of Holland's SDS summary codes in terms of career choice: A four-year follow-up

This study was designed to investigate the predictive efficiency of the primary and secondary summary codes of Holland's Self-Directed Search for Educational and Vocational Planning (SDS) in terms of expressed career choice 4 years later. In 1974, 126 voiationally undecided high school seniors were given the SDS, followed by a revision of Trow's Vocational Choice Inventory (VCI) in which they were asked to express a career choice or a state of indecision. In 1978, this same group was mailed a posttest VCI; the responses of 84 subjects were then analyzed. The subjects' expressed career choices on both the 1974 and 1978 VCI were compared to the primary and secondary summary codes on the SDS which they had taken in 1974. Inspection of the responses indicated that 21.4% of the subjects had made career choices predicted by their primary summary codes and 51.2% had made vocational choices found among their secondary summary codes. Only 27.4% chose a career area not predicted by their 1974 SDS results. The results of this study appear to lend support to the validity of using the SDS summary codes to predict eventual career decisions.     

Concurrent validity of Holland's theory for college degreed working women

The study was designed to explore two areas: (1) the concurrent validity of Holland's theory for employed college degreed women using two different operational definitions (Vocational Preference Inventory and the Self-Directed Search) of vocational orientation; and (2) the relationships among same named scales across the VPI and the SDS. Concurrent validity was studied by administering the VPI and the SDS to 179 women workers in occupational environments consistent with Holland's six vocational environments. In general, the findings indicate that the VPI and SDS scales tend to effectively discriminate among the occupational groups consistent with Holland's theoretical framework. In addition, the correlation coefficients for same named scales for the two inventories were all found to be significant. In sum, the results of the study lend some support to the concurrent validity of Holland's theory for employed college degreed women.     

风险偏好预测中的性别差异和框架效应

11 8名大学生被试在得益和损失两种任务框架下对自己、其他男性和女性的风险偏好进行了预测。结果发现 ,被试在损失框架下对各类对象风险偏好的预测均高于得益框架 ,且都高估了男性的风险偏好 ,低估了女性的风险偏好。在损失框架下 ,女性被试对各类对象的风险偏好预测高于男性的预测。研究认为 ,性别原型知识、任务框架和即时情绪共同影响被试的风险偏好预测。     

Population growth and social structure of confined colonies of mongolian gerbils: Scent gland size and marking behaviour as indices of social status

Male gerbils have larger ventral scent glands, and they mark more than females. In both sexes, scent gland activity is dependent on gonadal hormones. Observations on colonies of gerbils, living in enclosures or cages, showed that both scent gland size and marking behaviour were related to social status. In colonies founded by a single pair, breeding was confined to the original female. The infertility of the daughters was due to failure of sexual maturation. As this was always associated with a lack of development of the scent glands, the functional state of the latter could be used as an index of fecundity. A change in social organization (eg removal of the parents) caused previously infertile females to conceive and was accompanied by development of the scent glands If there was competition for dominance, the scent glands of the losers regressed; at autopsy, their ovaries and uteri appeared to be nonfunctional. The founding father usually had a larger scent gland than his sons, but the inhibition of sexual function was not as severe as in the females. However, the father characteristically showed much more marking behaviow in a neutral territory than his sons. None of the fem ales-except the mother-showed appreciable marking, and her scores were much lower than those of the dominant male. Asymptotic populations were reached at about the same level in enclosures and cages, implicating an intrinsic capacity for control independent of the number of animals per unit of space but probably related to the natural size of a social group. Stabilization of numbers was achieved not only by reproductive inhibition of young females, but also by cessation of breeding by the founding mother and death of litters. Littermates raised in enclosures without their parents showed delayed sexual maturation accompanied by fighting which resulted in the formation of a hierarchy headed by a breeding female and a dominant (marking) male.     

Who drops-out? Do measures of risk to self and to others predict unplanned endings in primary care counselling?

Aims: Unplanned endings, where clients unilaterally end therapy, are of concern for psychological therapy services generally as they raise questions about the appropriateness of the treatment and it's delivery for some clients. Limited available data indicates that those who drop-out often have more severe symptoms at entry, and have poorer clinical outcomes. This raises further questions about risk to self and others for those clients who leave therapy prematurely and how these clients might be identified and kept engaged. Method: This paper uses a large dataset of CORE data collected routinely in a primary care counselling service between 2000 and 2003. Logistic regression was utilised to consider different measures of risk and other client characteristics recorded at assessment to predict drop-out from the service. Results: These indicate that younger age, greater psychological distress at assessment, an addiction problem and greater risk to others, are associated with an unplanned ending. However, no reliable logistic regression model could be produced. This may be partly due to data quality issues or important characteristics not being available in the data. Implications for practice: The paper concludes that counsellors should actively seek to minimise unplanned endings, as amongst them may be represented the more distressed and risky clients referred to primary care counselling.