Bridging and Bonding in the Academic Melting Pot: Cultural Resources and Network Diversity

Understanding how cultural resources shape the formation of social networks is a methodological challenge as well as a theoretical objective, and both are yet to be met. In this study, sociability on college campuses is modeled as a process in which students’ prior cultural experiences and the current social structure of the student body work together, affecting the likelihood of friendships that take place within or across racial boundaries. Structural and cultural perspectives are surveyed to develop hypotheses concerning the determinants of interracial friendship, and these hypotheses are tested against a sample of 3,392 students from the National Longitudinal Study of Freshmen. The results suggest that religiosity, political activism, high arts participation, and athletic activities undertaken prior to college affect the diversity of social networks formed in the first year, but work in different directions. The effects of these cultural experiences may be explained by the racial organization of cultural activity on campus.     

Changes in At-Risk American Men's Crime and Substance Use Trajectories Following Fatherhood

Fatherhood can be a turning point in development and in men's crime and substance use trajectories. At-risk boys (N = 206) were assessed annually from ages 12 to 31 years. Crime, arrest, and tobacco, alcohol, and marijuana use trajectories were examined. Marriage was associated with lower levels of crime and less frequent substance use. Following the birth of a first biological child, men's crime trajectories showed slope decreases, and tobacco and alcohol use trajectories showed level decreases. The older men were when they became fathers, the greater the level decreases were in crime and alcohol use and the less the slope decreases were in tobacco and marijuana use. Patterns are consistent with theories of social control and social timetables.     

Teaching social work students

The evolution of the training methods described in this paper was based on a search for relevant material, in the eyes of the student as well as the lecturer. The cornerstone of our method was to create simulations of applied situations taken from student placement experiences, and tease out both the communication elements and the central issues relating to a number of particular social work concepts. In creating explicit linkage with placement experience, the principle of student choice, in terms of identifying situations and themes appropriate for simulation, was of importance. At the same time, we would emphasize the importance of the earlier social skills and social work inputs in the course, in laying a necessary foundation for the development in the student of an ability to benefit from the broader strategy adopted in the thematic approach.     

Screening procedures using quadratic forms

In quality control, a performance variable having a two-sided specification limit is common for assessing lot quality. Sometimes it is difficult or impossible to measure the performance variable directly; for example, when testing is destructive, expensive, or when the performance variable is related to the lifetime of the product. However, it may happen that there are several concomitant variables which are easily measured and which correlate highly with the variable of interest. Thus, one may use measurements on these variables to select or screen product which will have a high conditional probability of meeting product specification. We consider this situation when all variables have a joint multivariate normal distribution and the specification limits on the performance variable are two-sided.     

Telling a Good Story: Using Narratives in Vocational Rehabilitation With Veterans

Because of the high chronicity of work-related problems in a Veterans Administration Medical Center population, many of the traditional methods of career assessment, counseling, and placement have proven ineffectual. In this article the authors detail the development of an intervention based on narrative or storytelling principles. They describe efforts to introduce this model to patients as well as to relate patients' stories to vocational outcomes. The usefulness of stories as an organizing principle for counselors and clients is discussed, and suggestions are offered for further uses of storytelling interventions.     

Socio-economic effects of relative income and relative cohort size

A nonlinear three-stage least-squares technique is used to estimate a four-equation model in which age-specific fertility, marriage, divorce, and female labor force participation rates are the dependent variables. In addition to a range of explanatory variables, two proxies for the Easterlin hypothesis are tested within the model, one measuring relative income and the other measuring relative cohort size. Findings indicate that the Easterlin proxies, while not statistically significant in all cases, help to explain time-series movements in various socio-economic variables in the postwar United States.     

The Timing of Entry Into Fatherhood in Young, At-Risk Men

Timing of first fatherhood was examined in a sample of 206 at-risk, predominantly White men, followed prospectively for 17 years. An event history analysis was used to test a model wherein antisocial behavior, the contextual and familial factors that may contribute to the development of antisocial behavior, and common correlates of such behavior, including academic failure, substance use, and early initiation of sexual behaviors, lead both directly and indirectly to an early transition to fatherhood. Having a mother who was younger at first birth, low family SES, poor academic skills, failure to use condoms, and being in a cohabitating or marital relationship predicted entry into fatherhood. Implications of the findings for prevention of and intervention with early fathering are discussed.     

A scientist's viewpoint on promoting effective use of experimental design: Ten things a scientist wants to know about experimental design

This paper tackles the practical application of statistical tools. Chemical development is a rich area for collaboration between statisticians and chemists, but most statisticians encounter difficulties in promoting the tools to this client group. This paper, presented from a chemist's perspective, is intended to help bridge the gap between the two professions. The paper explores differences in uptake and attitudes towards adopting these techniques and suggests what has hindered or helped the process of effective application of experimental design. Copyright © 2003 John Wiley & Sons, Ltd.     

Propagation of Uncertainty in Risk Assessments: The Need to Distinguish Between Uncertainty Due to Lack of Knowledge and Uncertainty Due to Variability

In quantitative uncertainty analysis, it is essential to define rigorously the endpoint or target of the assessment. Two distinctly different approaches using Monte Carlo methods are discussed: (1) the end point is a fixed but unknown value (e.g., the maximally exposed individual, the average individual, or a specific individual) or (2) the end point is an unknown distribution of values (e.g., the variability of exposures among unspecified individuals in the population). In the first case, values are sampled at random from distributions representing various "degrees of belief" about the unknown "fixed" values of the parameters to produce a distribution of model results. The distribution of model results represents a subjective confidence statement about the true but unknown assessment end point. The important input parameters are those that contribute most to the spread in the distribution of the model results. In the second case, Monte Carlo calculations are performed in two dimensions producing numerous alternative representations of the true but unknown distribution. These alternative distributions permit subject confidence statements to be made from two perspectives: (1) for the individual exposure occurring at a specified fractile of the distribution or (2) for the fractile of the distribution associated with a specified level of individual exposure. The relative importance of input parameters will depend on the fractile or exposure level of interest. The quantification of uncertainty for the simulation of a true but unknown distribution of values represents the state-of-the-art in assessment modeling.