In 1987 the federal government permitted states to raise the speed limit on their rural interstate roads, but not on their urban interstate roads, from 55 mph to 65 mph. Since the states that adopted the higher speed limit must have valued the travel hours they saved more than the fatalities incurred, this institutional change provides an…

The authors evaluated 4 sequential sampling models for 2-choice decisions--the Wiener diffusion, Ornstein-Uhlenbeck (OU) diffusion, accumulator, and Poisson counter models--by fitting them to the response time (RT) distributions and accuracy data from 3 experiments. Each of the models was augmented with assumptions of variability across trials in…

To assess the reliability of congeneric tests, specifically designed reliability measures have been proposed. This paper emphasizes that such measures rely on a unidimensionality hypothesis, which can neither be confirmed nor rejected when there are only three test parts, and will invariably be rejected when there are more than three test parts.…

The DA-T Gibbs sampler is proposed by Maris and Maris (2002) as a Bayesian estimation method for a wide variety of "Item Response Theory (IRT) models". The present paper provides an expository account of the DA-T Gibbs sampler for the 2PL model. However, the scope is not limited to the 2PL model. It is demonstrated how the DA-T Gibbs…

One purpose of educational research is to provide information about the likely impact of interventions or treatments on policy-relevant populations of students. Randomized experiments are useful for estimating the causal effects of interventions on the students in schools that participate in the experiments. Unfortunately, the samples of schools…

Empirical evidence is presented related to the effects of using a stratified sampling of items in multiple matrix sampling on the accuracy of estimates of the population mean. Data were obtained from a sample of 600 high school students for a 36-item mathematics test and a 40-item vocabulary test, both subtests of the Iowa Tests of Educational…

Technical considerations associated with item selection and reliability assessment are considered in relation to criterion-referenced tests constructed to provide group information. The purpose is to emphasize test building and the evaluation of test scores in program evaluation studies. It is stressed that an evaluator employ a performance or…

Objective: The authors used a stratified cluster sampling design to inform campus sexually transmitted diseases prevention programs. Participants and Methods: They conducted a cross-sectional study of students (N = 1,130) at a large, urban, minority-serving university in South Florida using the 2004 National College Health Assessment Survey…

Although SAS PROC CALIS is not designed to perform multigroup comparisons, it is believed that SAS can be "tricked" into doing so for groups of equal size. At present, there are no comprehensive examples of the steps involved in performing a multigroup comparison in SAS. The purpose of this article is to illustrate these steps. We demonstrate…

Previous studies have shown that active consent procedures result in sampling bias in surveys dealing with adolescent risk behaviors such as cigarette smoking and illicit drug use. To examine sampling bias from active consent procedures when the survey topic pertains to childhood obesity and associated health behaviors, the authors pair data…

The focus of the study was on empirically providing a composite picture of the relationship of some representatives of school, student and teacher factors on students' environmental conservation habit of a school-based Environmental Education programme. The study sample comprised 584 members of the Nigerian Conservation Foundation (NCF) School…

Concerns about the importance of variation in statistics education and a lack of research in this topic led to a preliminary study which explored pre-service teachers' ideas in this area. The teachers completed a written questionnaire about variation in sampling and distribution contexts. Responses were categorised in relation to a framework that…

Using meta-analysis, randomized experiments in education that either clearly did or clearly did not experience student attrition were examined for the baseline comparability of groups. Results from 35 studies suggested that after attrition, the observed measures of baseline comparability of groups did not differ more than would be expected given…

In this study, I explore the experiences of five Japanese returnees ("kikokushijo"). The participants recorded taped monologues or wrote narratives reflecting on their time spent living abroad and of returning to Japan. These retrospective life stories revealed four prominent themes of conflict: group orientation; bullying and…

The multiple segment factorial vignette design (MSFV) combines elements of experimental designs and probability sampling with the inductive, exploratory approach of qualitative research. MSFVs allow researchers to investigate topics that may be hard to study because of ethical or logistical concerns. Participants are presented with short stories…