Casino gambling in private school and adjudicated youngsters: A survey of practices and related variables

This study provides additional information about casino gambling practices in two adolescent samples. Specifically, 109 adolescents from a religious high school and 84 adolescents from a juvenile detention facility in Las Vegas, Nevada were surveyed. Of these, 71 (36.8%) were found to gamble regularly (58 males, 13 females, mean age 15.9 years). Results indicated many similarities among the two groups. The overall sample appeared to have a strong affinity for casino gambling, were diverse in their practices and reasons for gambling, reported a variety of emotional and physiological behaviors when gambling, occasionally experienced problems from casino gambling, and had parents who generally approved and were aware of their children's gambling behavior. The accessibility and family-oriented nature of many new casinos may be responsible for these effects.The authors thank Nicole Giangregorio and Ned C. Silver for their assistance. Portions of this paper were presented at the meeting of the Rocky Mountain Psychological Association, Boulder, CO.     

Combining an Internal Pilot with an Interim Analysis for Single Degree of Freedom Tests

An internal pilot with interim analysis (IPIA) design combines interim power analysis (an internal pilot) with interim data analysis (two-stage group sequential). We provide IPIA methods for single df hypotheses within the Gaussian general linear model, including one and two group t tests. The design allows early stopping for efficacy and futility while also re-estimating sample size based on an interim variance estimate. Study planning in small samples requires the exact and computable forms reported here. The formulation gives fast and accurate calculations of power, Type I error rate, and expected sample size.     

On the Use of a Log-Rate Model for Survey-Weighted Categorical Data

For the analysis of survey-weighted categorical data, one recommended method of analysis is a log-rate model. For each cell in a contingency table, the survey weights are averaged across subjects and incorporated into an offset for a loglinear model. Supposedly, one can then proceed with the analysis of unweighted observed cell counts. We provide theoretical and simulation-based evidence to show that the log-rate analysis is not an effective statistical analysis method and should not be used in general. The root of the problem is in its failure to properly account for variability in the individual weights within cells of a contingency table. This results in goodness-of-fit tests that have higher-than-nominal error rates and confidence intervals for odds ratios that have lower-than-nominal coverage.     

Equal probability of correct selection for bernoulli selection procedures

The problem of selecting the Bernoulli population which has the highest "success" probability is considered. It has been noted in several articles that the probability of a correct selection is the same, uniformly in the Bernoulli p-vector (P1,P2,….,Pk), for two or more different selection procedures. We give a general theorem which explains this phenomenon.

An application of particular interest arises when "strong" curtailment of a single-stage procedure (as introduced by Bechhofer and Kulkarni (1982a) )is employed; the corresponding result for "weak" curtailment of a single-stage procedure needs no proof. The use of strong curtailment in place of weak curtailment requires no more (and usually many less) observations to achieve the same.     

Correlation is first order independent of transformation

We show that the correlation between the estimates of two parameters is almost unchanged if they are each transformed in an arbitrary way. To be more specific, the correlation of two estimates is invariant (except for a possible sign change) up to a first order approximation, to smooth transformations of the estimates. There is a sign change if exactly one of the transformations is decreasing in a neighborhood of its parameter. In addition, we approximate the variance, covariance and correlation between functions of sample means and moments.     

Statistical Inference Enables Bad Science; Statistical Thinking Enables Good Science

ABSTRACT

Scientific research of all kinds should be guided by statistical thinking: in the design and conduct of the study, in the disciplined exploration and enlightened display of the data, and to avoid statistical pitfalls in the interpretation of the results. However, formal, probability-based statistical inference should play no role in most scientific research, which is inherently exploratory, requiring flexible methods of analysis that inherently risk overfitting. The nature of exploratory work is that data are used to help guide model choice, and under these circumstances, uncertainty cannot be precisely quantified, because of the inevitable model selection bias that results. To be valid, statistical inference should be restricted to situations where the study design and analysis plan are specified prior to data collection. Exploratory data analysis provides the flexibility needed for most other situations, including statistical methods that are regularized, robust, or nonparametric. Of course, no individual statistical analysis should be considered sufficient to establish scientific validity: research requires many sets of data along many lines of evidence, with a watchfulness for systematic error. Replicating and predicting findings in new data and new settings is a stronger way of validating claims than blessing results from an isolated study with statistical inferences.     

Multiple roots of estimating functions

Estimating functions can have multiple roots. In such cases, the statistician must choose among the roots to estimate the parameter. Standard asymptotic theory shows that in a wide variety of cases, there exists a unique consistent root, and that this root will lie asymptotically close to other consistent (possibly inefficient) estimators for the parameter. For this reason, attention has largely focused on the problem of selecting this root and determining its approximate asymptotic distribution. In this paper, however, we concentrate on the exact distribution of the roots as a random set. In particular, we propose the use of higher-order root intensity functions as a tool for examining the properties of the roots and determining their most problematic features. The use of root intensity functions of first and second order is illustrated by application to the score function for the Cauchy location model.     

Implicit prejudicial biases in student learning: the effects of sexual orientation

In an investigation of students' potential biases toward gay and lesbian instructors, 93 female and 59 male undergraduates viewed a lecture, rated the instructor and perceived learning, and completed a lecture-retention test. Lectures were given by a man or woman, identified as straight or gay or lesbian. Sexual orientation did not affect the instructor evaluation or perceived learning ratings for any of the groups. Although sexual orientation did not affect the lecture-retention scores for the female students, learning by the male students was significantly lower with the gay male instructor than with the straight male instructor (p = .03), suggesting an implicit bias.     

Francine Blau receives IZA Prize in Labor Economics

News

Francine Blau receives IZA Prize in Labor Economics     

Failures in Child Protection: A Case Study

A case example is used to illustrate how powerful a child abuser may become; where a complex hostage-type relationship develops between family members and is then extended to include the child protection worker. One consequence of this is the increased risk of re-abuse of the children. To establish this relationship the abuser uses a number of techniques such as violence, intimidation, isolation and unpredictability. In the case presented, the three children were subjected to ongoing severe abuse, although the child protection agency had known the family for 10 years. The children often denied and hid the abuse, and the child protection workers were left largely unsupported by other professionals and often appeared to comply with the wishes of the abusing parents. © 1997 by John Wiley & Sons, Ltd.