A Bayesian Semiparametric Item Response Model with Dirichlet Process Priors

In Item Response Theory (IRT), item characteristic curves (ICCs) are illustrated through logistic models or normal ogive models, and the probability that examinees give the correct answer is usually a monotonically increasing function of their ability parameters. However, since only limited patterns of shapes can be obtained from logistic models or normal ogive models, there is a possibility that the model applied does not fit the data. As a result, the existing method can be rejected because it cannot deal with various item response patterns. To overcome these problems, we propose a new semiparametric IRT model using a Dirichlet process mixture logistic distribution. Our method does not rely on assumptions but only requires that the ICCs be a monotonically nondecreasing function; that is, our method can deal with more types of item response patterns than the existing methods, such as the one-parameter normal ogive models or the two- or three-parameter logistic models.     

Religiosity, Spirituality, and the Subjective Quality of African American Men's Friendships: An Exploratory Study

The present study fills a crucial gap in literature surrounding the lives of African American men by exploring factors that shape the quality of these men's friendships. Drawing on data from a sample of 171 African American men, the study examines the relative utility of subjective religiosity, subjective spirituality, advice exchange, and affective sharing as predictors of the level of perceived support from male and female friends. Findings reveal age differences in subjective religiosity, subjective spirituality, and in level of advice and affective exchange in men's same-sex as well as cross-sex friendships. Age differences emerged in men's perceptions of the supportiveness of their friendships with women but not with men. Age was not a predictor of perceived supportiveness of same-sex or cross-sex friendships. Subjective religiosity did not predict support in same-sex or cross-sex friendships. Subjective spirituality positively predicted perceived support in men's same-sex friendships but not in cross-sex friendships. Implications of these findings are discussed.     

Where we stand today in the practice of evaluation: Some reflections

It is a great pleasure and privilege to be here in The Hague this morning to help celebrate what we hope will be a first historic meeting of the European Evaluation Society. It’s a happy day, not only because of the international character of this group and its impressive collective credentials, but also because this conference fits so well into the generally high hopes and expectations that we have for evaluation today. Eleanor Chelimsky is GAO’s Assistant Comptroller General for Program Evaluation. Since 1980, she has directed GAO’s Program Evaluation and Methodology Division. Chelimsky is a member of the advisory boards for the University of Chicago’s School of Social Service Administration and for Camegie-Mellon’s John Heinz School of Public Policy. She is also a member of the editonal review board for the Sage Research Series in Evaluation and serves on the editorial boards of two joumals:Policy Studies Review andPolicy Studies Review Annual.     

Self-discrepancy and Depressive Experiences among Chinese Early Adolescents: Significance of Identity and the Undesired Self

The paper addresses the cultural bias in the conceptualization and assessment of the self construct inherent in self-discrepancy theory proposed by Higgins. It argues that discrepancies between actual and undesired selves conceived in terms of salient identity should be better predictors of depressive experiences among Chinese early adolescents than the popular notion of actual:ideal discrepancies conceived in terms of individuated self. Eighty-four Chinese early adolescents drawn from the normal population in Hong Kong participated in the study, adopting a short-term two-wave prospective design. Empirical support was obtained showing that self-discrepancies conceived in terms of salient identity and discrepancies between actual and undesired selves were stronger predictors of depressive experiences over time. The findings were interpreted from the perspectives of Chinese culture and the development of self understanding.     

Effects of Gender and Profession Type on Definitions of Violence Against Women in Hong Kong

This study investigated the criteria chosen by male and female Chinese public servants (clinical psychologists, social workers, police officers, physicians, nurses, teachers, and lawyers) in Hong Kong to classify and define violence against women. Data were gathered via questionnaires completed by 2589 (686 male) public servants from 10,476 polled (response rate 24.7%). The questionnaires included a 14-item check-list of various behaviors constituting violence against women and a 10-item check-list of criteria that could be used to categorize behavior as violence against women. It was found that for this population, use of physical force and lack of consent were the main determinants of violence against women. Only half of respondents considered murder a form of violence against women, the rest categorized it as a crime that was "not merely violence." Most respondents defined sexual harassment, rape, and unwanted physical contact as forms of violence against women. The female public servants were more likely to define behaviors as violence against women and to use more criteria to define violence against women. Public servants who worked with the law enforcement and legal system were more likely than others to choose narrow definitions and rigid criteria.     

Measures of play behavior: The influence of sex-role stereotyped children's books

Preschool children significantly more often chose a sex-stereotypic toy following exposure to a sex-stereotypic children's book. Conversely, boys and girls exposed to a nonstereotypic book significantly more often selected a nonstereotypic toy. Boys and girls individually played with stereotypic male, female, and neutral toys; each child was then read a sex-role stereotypic or nonstereotypic picture book; another play session followed. Measures of visual regard and manipulation were applied to the observed play behavior of 32 preschool children to determine the significance of the findings.     

Family resemblances: Studies in the internal structure of categories

Six experiments explored the hypothesis that the members of categories which are considered most prototypical are those with most attributes in common with other members of the category and least attributes in common with other categories. In probabilistic terms, the hypothesis is that prototypicality is a function of the total cue validity of the attributes of items. In Experiments 1 and 3, subjects listed attributes for members of semantic categories which had been previously rated for degree of prototypicality. High positive correlations were obtained between those ratings and the extent of distribution of an item's attributes among the other items of the category. In Experiments 2 and 4, subjects listed superordinates of category members and listed attributes of members of contrasting categories. Negative correlations were obtained between prototypicality and superordinates other than the category in question and between prototypicality and an item's possession of attributes possessed by members of contrasting categories. Experiments 5 and 6 used artificial categories and showed that family resemblance within categories and lack of overlap of elements with contrasting categories were correlated with ease of learning, reaction time in identifying an item after learning, and rating of prototypicality of an item. It is argued that family resemblance offers an alternative to criterial features in defining categories.     

Basic objects in natural categories

Categorizations which humans make of the concrete world are not arbitrary but highly determined. In taxonomies of concrete objects, there is one level of abstraction at which the most basic category cuts are made. Basic categories are those which carry the most information, possess the highest category cue validity, and are, thus, the most differentiated from one another. The four experiments of Part I define basic objects by demonstrating that in taxonomies of common concrete nouns in English based on class inclusion, basic objects are the most inclusive categories whose members: (a) possess significant numbers of attributes in common, (b) have motor programs which are similar to one another, (c) have similar shapes, and (d) can be identified from averaged shapes of members of the class. The eight experiments of Part II explore implications of the structure of categories. Basic objects are shown to be the most inclusive categories for which a concrete image of the category as a whole can be formed, to be the first categorizations made during perception of the environment, to be the earliest categories sorted and earliest named by children, and to be the categories most codable, most coded, and most necessary in language.     

A developmental study of visual search behavior

Children in second, fourth and sixth grades and college sophomores were compared on a visual search and scanning task under three experimental conditions. In Condition I, a single target letter was sought in a list of letters of low visual confusability. In Condition II, two target letters were sought but only one appeared in a given list. In Condition III, a single target letter was sought in a list of letters of high confusability. Search time decreased with age in all three tasks. Searching for two targets was no harder than searching for one. A highly confusable visual context increased search time at all age levels.