An evaluation of the fidelity of implementation of a school-based drug abuse prevention program: project toward no drug abuse (TND)

This article provides an implementation fidelity evaluation of the fourth experimental trial of Project Towards No Drug Abuse (TND). Two theoretical content components of the curriculum were examined to increase our understanding of the active ingredients of successful drug abuse prevention programs. A total of 18 senior high schools were randomly assigned by block to receive one of three conditions: cognitive perception information curriculum, cognitive perception information + behavioral skills curriculum, or standard care (control). These curricula were delivered to both regular and continuation high schools students (n=2331) by trained project health educators and regular classroom teachers. Across all program schools, the two different curricula were implemented as intended, were received favorably by students, and showed significant improvements in knowledge specific to the theoretical content being delivered. This pattern of results suggests that the experimental manipulations worked as intended, and thus, permit the attribution of future behavioral outcome differences between conditions to differences in content of Project TND material provided rather than to differences in the fidelity of delivery. Further, our findings indicate that Project TND can be implemented effectively with low and high risk youth in a general environment as well as with high risk youth in a more specialized environment.     

Brief Family Therapy: A Metaphorical Task

This article presents a therapeutic procedure designed to prescribe, in metaphorical form, the family's troublesome behavior pattern. Particular attention is paid to using a compliment to precede delivering a task assignment as a method of increasing the likelihood that the family will perform the task, and thus change will be promoted. A case example is used to illustrate the use of this procedure to help make change less painful.     

The Social Work Assessment Tool (SWAT)

This paper reports on the last of three National Hospice and Palliative Care Organization initiatives to move hospice and palliative care social workers into the patient/family outcomes arena: the development of the Social Work Assessment Tool. The experience of a team of practitioners and researchers is described, including results of two pilot studies and subsequent SWAT revisions. The major focus is on the current model performance improvement project, in which 19 social workers from 14 hospice and palliative care programs used the SWAT with 101 patients and 81 primary caregivers for a median of 44 days. Quantitative analysis indicated significant improvement in SWAT scores for patients from the first to the second social work visit (t = -2.60, df = 47, p .01). Qualitative interviewing of the social workers indicated some lack of readiness in the field to conduct quantitative outcomes measurement. Additional measures are needed in addition to the SWAT, including qualitative measures, and measures of mezzo and macro practice. Participants indicated that the SWAT was appropriate for use with economically and culturally diverse clients.     

A stepwise algorithm for selecting category boundaries for the chi-squared goodness-of-fit test

A stepwise algorithm for selecting categories for the chisquared goodness-of-fit test with completely specified continuous null and alternative distributions is described in this paper. The procedure's starting point is an initial partitioning of the sample space into a large number of categories. A second partition with one fewer category is constructed by combining two categories of the original partition. The procedure continues until there are only two categories; the partition in the sequence with the highest estimated power is the one chosen. For illustartive purposes, the performance of the algorithm is evaluated for several hypothesis tests of the from H₀: normal distribution vs. H₁: a specific mixed normal distribution. For each test considered, the partition identified by the algorithm was compared to several equiprobable partitions, including the equiprobable partition with the highest estimated power. In all cases but one, the algorithm identified a parttion with higher estimated power than the best equiprobable partition. Applciations of the procedure are discussed.     

A test for variance-covarianch parameters in normal linear models

This paper derives a test statistic for the variance-covariance parameters which is a quadratic function of their MINQUE (Minimum Norm Quadratic Unbiased Estimation) estimates. The test is a Wald-type test, and its development closely parallels the theory used to derive a similar test for the coefficients in linear models. In fact, the derivation proceeds by first setting up the estimation problem in a derived linear model in which the dispersion parameters are the coefficients. The test statistic is shown to be the sum of the squares of independent standardized x² variables.     

Optimal testing in a three way anova model

We consider likelihood ratio, score and Wald tests for a three-way random effects ANOVA model. Competitor tests are compared using criteria such as small sample power, asymptotic relative efficiency, and convenient null distribution. The final choice is between a new test and two tests long used in practice.     

Tests for Symmetry Based on the One-Sample Wilcoxon Signed Rank Statistic

ABSTRACT

The one-sample Wilcoxon signed rank test was originally designed to test for a specified median, under the assumption that the distribution is symmetric, but it can also serve as a test for symmetry if the median is known. In this article we derive the Wilcoxon statistic as the first component of Pearson's X ² statistic for independence in a particularly constructed contingency table. The second and third components are new test statistics for symmetry. In the second part of the article, the Wilcoxon test is extended so that symmetry around the median and symmetry in the tails can be examined seperately. A trimming proportion is used to split the observations in the tails from those around the median. We further extend the method so that no arbitrary choice for the trimming proportion has to be made. Finally, the new tests are compared to other tests for symmetry in a simulation study. It is concluded that our tests often have substantially greater powers than most other tests.