Cross-national comparative analysis of tobacco control strategies can alert health advocates to how opportunities for public health action, types of action, and probabilities for success are shaped by political systems and cultures. This article is based on case studies of tobacco control in the United States, Canada, Britain, and France. Two…

A linear classification rule (used with equal covariance matrices) was contrasted with a quadratic rule (used with unequal covariance matrices) for accuracy of internal and external classification. The comparisons were made for seven situations which resulted from combining three data conditions (equal and unequal covariance matrices, minimal and…

This paper will discuss the results of a series of computer simulations comparing the Rasch logistic model to a series of models departing to various degrees from its assumption of equal discrimination power for all items. The results have implications for test construction and test scoring, indicating how closely the conventional raw score…

This paper summarizes the thinking of 84 middle school mathematics students' about variability in three stochastics tasks that involve repeated trial. Differences in students' acknowledgment of variability were found, depending on whether the task was from a sampling environment, or a probability environment. Students tended to neglect variability…

Five models which perform search tasks of the Data Base Access and Search Environment (DBASE) are presented and used for comparison with subject search performance--unconstrained (rule-based, decision theoretic) and constrained (optimal rule-based, rule-based, probabilistic rule-based). Previous experiments and the modeling approach are briefly…

Describes the Belief Function Model for automatic indexing and ranking of documents which is based on a controlled vocabulary and on term frequencies in each document. Belief Function Theory is explained, and the Belief Function Model is compared to the Standard Vector Space Model. (17 references) (LRW)

Background: Research has shown that a large proportion of adolescents with symptoms of depression and substantial distress or impairment fail to meet the diagnostic criteria for a major depressive disorder (MDD). However, many of these undiagnosed adolescents may meet criteria for a residual category of the "Diagnostic and Statistical Manual of…

Two fundamental problems in mental test theory are to estimate true score and to estimate the amount of error when testing an examinee. In this report, three probability models which characterize a single test item in terms of a population of examinees are described. How these models may be modified to characterize a single examinee in terms of an…

Comparing variability of test scores across alternate forms, test conditions, or subpopulations is a fundamental problem in psychometrics. A confidence interval for a ratio of standard deviations is proposed that performs as well as the classic method with normal distributions and performs dramatically better with nonnormal distributions. A simple…

Despite its apparent simplicity, random assignment is an abstract concept for many students. This article describes a classroom demonstration that uses a standard deck of playing cards. In small groups, students randomly assign playing cards (i.e., participants) to 2 treatment groups. Following randomization, students compare the relative…

With growing numbers of drug-involved offenders, substance abuse treatment has become a critical part of corrections. A multistage therapeutic community implemented in the Delaware correctional system has as its centerpiece a residential treatment program during work release--the transition between prison and community. An evaluation of this…

This paper reports a causal-comparative study of science anxiety among Form Four students in Penang. The Wynstra's (1991) Science Anxiety Inventory (SAI), which consists of six factors (i.e., danger anxiety, science test anxiety, math and problem-solving anxiety, squeamish anxiety, performance anxiety, and science classroom anxiety), was…

This study examines the effects on the National Assessment of Educational Progress (NAEP) achievement levels of using item response theory (IRT) models that have nominal missing-response parameters. It compares cutpoints based on item parameters that were fitted using two different models. The first set of cutpoints were based on parameters for…

Item characteristic curve (ICC) theory describes the relationship between the ability of individuals and the probability of their answering a test question correctly; it is useful in estimating test scores, equating the scores of various tests, and scoring responses during adaptive testing. A simulation study of the effectiveness of the following…

The power of the classical Linear Discriminant Function (LDF) is compared, using Monte Carlo techniques with five other procedures for classifying observations from certain non-normal distributions. The alternative procedures considered are the Quadratic Discriminant Function, a Nearest Neighbor Procedure with Probability Blocks, and three density…