Formative evaluation of a motivational intervention for increasing physical activity in underserved youth

The present study was designed to develop an innovative motivational intervention (based on Self-Determination Theory and Social Cognitive Theory) to increase physical activity (PA) in underserved adolescents. Sixty-four adolescents (35 females, 29 males; 50% minority; 65% on reduced lunch program; ages 11-13 yr) participated in either an 8-week motivational intervention after-school (n = 32) or a typical after-school program (n = 32). The conceptual framework for the intervention targeted the social environment (perceived autonomy, perceived social support, participation, fun), cognitive mediators (perceived choice, self-efficacy, and relatedness/belongingness), and motivational orientation (intrinsic motivation, commitment, positive self-concept). Formative evaluation data was collected by staff through daily forms throughout the 8-week program and through observational data completed by independent objective observers during 2 weeks of the program. The major themes that were identified addressed theoretical concepts regarding the intervention and logistical issues in delivering the intervention. The data revealed information regarding the importance of the cognitive appropriateness of the PA and motivational activities, the environmental climate for promoting nurturing relationships, developing specific strategies for increasing intrinsic rather than extrinsic reinforcement, and developing methods for preventing social "cliques" and gender conflicts to maintain an appropriate level of support in the social climate. Themes for training staff included focusing on team building, leadership, and nurturing. This formative evaluation is being used to formalize a randomized trial to test the effects of a student-centered motivational intervention on increasing PA in underserved 6th graders.     

Long-term effects of teaching behavioral strategies for managing persistent auditory hallucinations in schizophrenia

1. Attendance at a 10-week class designed to teach behavioral management strategies to people with schizophrenia was effective in reducing some of the negative characteristics of auditory hallucinations for 12 months and in reducing anxiety for 9 months after completion of the class. 2. The sustained improvement experienced by class participants was characterized by their voices being less frequent and more mumbled and the participants feeling more in control, less distractible, and less anxious. 3. Participants recommended that other mental health consumers take similar classes to learn how to better manage their voices. 4. Monthly support groups may help participants maintain gains lost during the follow-up period.     

Social skills, competence, and drug refusal efficacy as predictors of adolescent alcohol use

Numerous alcohol and drug abuse prevention trials have included social resistance training as a strategy for reducing early-stage adolescent alcohol use. Evaluations of these trials has shown them to be moderately effective, although the precise impact of the resistance training in comparison to other programmatic features has not been clearly identified. The current study examined the extent to which assertiveness and related social skills, personal competence (perceived cognitive mastery), and refusal efficacy predict alcohol involvement. Males were at greater risk for poor refusal skills and reported higher alcohol involvement. Cross-sectionally, youth characterized by poor social skill development reported lower refusal efficacy, lower grades, poor competence, and more alcohol use. Poor refusal efficacy was associated with more risk-taking, lower grades, less competence, and more alcohol use. Longitudinally, both poor refusal skills and risk-taking were associated with higher alcohol use. High personal competence was associated with lower alcohol use in both the eighth and tenth grades, but had no long-term effects on alcohol use. Findings highlight the close interplay between perceived competence and refusal skill efficacy, both of which should be included as essential components of school-based prevention strategies.     

Research records and the resolution of misconduct allegations at research universities

Accurate record keeping is an important part of the responsible conduct of research. However, there is very little empirical research on scientific record keeping. No one knows the incidence of serious problems with research records, the types of problems that occur, nor their consequences. In this study, we examined the role of research records in the resolution of misconduct allegations as a useful barometer for the incidence and types of problems that occur with records. We interviewed Research Integrity Officers (RIOs) at 90 major research universities and conducted focus groups with active research faculty. RIOs reported problems with research records in 38% of the 553 investigations they conducted. Severe problems with research records often prevented completion of investigations while problems that are more typical lengthened them by 2 to 3 weeks. Five types of poor record keeping practices accounted for 75 % of the problems with incomplete/inadequate records being the most common (30%). The focus groups concurred with the findings from the interviews with RIOs, stressed the importance of the research group leader in setting and maintaining record practices, and offered additional insights. While university officials and faculty members have suspected for many years that there are serious problems with research record keeping, our study provides empirical evidence for this belief. By documenting some of the problems with record keeping in university-based research, the results of our study provide information that will be useful for policy development at academic institutions.     

Tracing the Density Impulse in Rural Settlement Systems: A Quantitative Analysis of the Factors Underlying Rural Population Density Across South-Eastern Australia, 1981–2001

Rural population density has a very significant independent influence over important socio-economic and demographic characteristics of developed world rural communities. Additionally, it is a fundamental variable in public policy and planning, both expressing and influencing the relative cost-efficiency of servicing populations. Yet density is itself produced by more fundamental qualities (e.g. environmental resources, nature and time of colonisation) which may themselves change over time. Treating rural population density as a dependent variable produced by a wide variety of factors, we build and test two causal models that attempt to explain the observed pattern of rural densities across south-eastern Australia (n = 414 communities). We distinguish between a “productivist” model—applicable for most of white Australia’s history—and a consumptionist model that takes account of recent counter-urbanisation trends. These models are applied to the entire study area and, in recognition of the study area’s internal heterogeneity, to five clusters of communities. In the drier inland and remoter zones, the productivist model exhibits the greatest explanatory power, while in the more accessible and well-watered “multifunctional” zones, an expanded model that incorporates a measure of “amenity” produces the best results. The research finds that simple environmental factors, coupled with relative location within the national space economy, act as dominant controls over rural population density in early 21st century Australia.

Beliefs of Guilt and Recommended Sentence as a Function of Juror Bias in the O. J. Simpson Trial

During the week of April 9, 1995, 125 male participants completed a questionnaire assessing attitudes toward the O. J. Simpson trial. Specifically, participants reported their belief in the defendant's guilt or innocence, stated how fair they perceived the trial to be, and recommended a sentence should the defendant be found guilty of the crime. Additionally, participants completed Kassin and Wrightsman's Juror Bias Scale and the revised California F scale. Overall, results showed that participants' scores on both scales were positively correlated with their beliefs in the defendant's guilt, perceived trial fairness, and more severe sentence recommendations.     

American Community Survey overview and the role of external evaluations

In 2010 the U.S. Census Bureau will achieve its goal of eliminating the long form sample from the decennial census and will produce its first set of five-year data products from the full sample American Community Survey (ACS). This paper provides an overview of the call for change that prompted the Census Bureau to pursue the development of a new approach to collecting socioeconomic and housing data. The paper details the evolution of the ACS from its earliest origins to its current design and describes that design in detail. The current design has benefited from external debate and consultation. Work such as that described later in this journal exemplifies the key role that external users and advisors have played, and will continue to play, in the evolution of the ACS. Over the past 10 years, the Census Bureau has undertaken research and testing to demonstrate operational feasibility and to assess survey quality. Research has also compared ACS and Census 2000 data. ACS staff are involved in survey improvement efforts and continue to confront survey challenges. In the next few years the ACS will give priority to developing user tools to aid all users in the correct interpretation of multi-year estimates. The ultimate validation of the ACS is, however, in the hands of users. Continued input from the people who are responsible for administering and evaluating programs, identifying local needs, and planning for the future will allow the ACS to grow in value and utility.     

Sequential Monte Carlo methods for mixtures with normalized random measures with independent increments priors

Normalized random measures with independent increments are a general, tractable class of nonparametric prior. This paper describes sequential Monte Carlo methods for both conjugate and non-conjugate nonparametric mixture models with these priors. A simulation study is used to compare the efficiency of the different algorithms for density estimation and comparisons made with Markov chain Monte Carlo methods. The SMC methods are further illustrated by applications to dynamically fitting a nonparametric stochastic volatility model and to estimation of the marginal likelihood in a goodness-of-fit testing example.     

Deriving the Normal and Exponential Densities Using EDA Techniques

This paper shows how students in an introductory statistics course discover mathematical expressions for the normal and exponential density functions. Techniques of exploratory data analysis (EDA) are applied to large data sets, the key idea being a straight-line fit to an appropriate reexpression of the histogram.     

Cross-validation prior choice in Bayesian probit regression with?many covariates

This paper examines prior choice in probit regression through a predictive cross-validation criterion. In particular, we focus on situations where the number of potential covariates is far larger than the number of observations, such as in gene expression data. Cross-validation avoids the tendency of such models to fit perfectly. We choose the scale parameter c in the standard variable selection prior as the minimizer of the log predictive score. Naive evaluation of the log predictive score requires substantial computational effort, and we investigate computationally cheaper methods using importance sampling. We find that K-fold importance densities perform best, in combination with either mixing over different values of c or with integrating over c through an auxiliary distribution.