Inference is considered for the marginal distribution of "X" when ("X", "Y") has a truncated bivariate normal distribution. The "Y" variable is truncated, but only the "X" values are observed. A sample of 87 Otis test scores is shown to be well described by this model. (SLD)

Goodness-of-fit (GOF) indexes provide "rules of thumb"?recommended cutoff values for assessing fit in structural equation modeling. Hu and Bentler (1999) proposed a more rigorous approach to evaluating decision rules based on GOF indexes and, on this basis, proposed new and more stringent cutoff values for many indexes. This article discusses…

Many statistics educators believe that few students develop the level of conceptual understanding essential for them to apply correctly the statistical techniques at their disposal and to interpret their outcomes appropriately. It is also commonly believed that the sampling distribution plays an important role in developing this understanding.…

Purpose: The purpose of this study was to review research published by Educational Administration Quarterly (EAQ) during the past 10 years to determine if confidence intervals and effect sizes were being reported as recommended by the American Psychological Association (APA) Publication Manual. Research Design: The author examined 49 volumes of…

Multilevel models are proven tools in social research for modeling complex, hierarchical systems. In multilevel modeling, statistical inference is based largely on quantification of random variables. This paper distinguishes among three types of random variables in multilevel modeling--model disturbances, random coefficients, and future response…

There is much research that documents what many teachers know, that students struggle with many concepts in probability and statistics. This article presents two sample activities the authors use to help preservice teachers develop ideas about how they can use technology to promote their students' ability to understand mathematics and connect…

Two analyses of variance (ANOVA) models for item scores are compared. The first is an items by subject random effect ANOVA. The second is a mixed effects ANOVA with items fixed and subjects random. Comparisons regarding reliability, Cronbach's alpha coefficient, psychometric inference, and inter-item covariance structure are made between the…

A subset of Statistical Process Control (SPC) methodology known as Control Charting is introduced. SPC methodology is a collection of graphical and inferential statistics techniques used to study the progress of phenomena over time. The types of control charts covered are the null X (mean), R (Range), X (individual observations), MR (moving…

Authors who write introductory business statistics texts do not agree on when to use a t distribution and when to use a Z distribution in both the construction of confidence intervals and the use of hypothesis testing. In a survey of textbooks written in the last 15 years, we found the decision rules to be contradictory and, at times, the…

The challenges of modeling students' performance in simulation-based assessments include accounting for multiple aspects of knowledge and skill that arise in different situations and the conditional dependencies among multiple aspects of performance in a complex assessment. This paper describes a Bayesian approach to modeling and estimating…

Contrasts aptitude by treatment interaction (ATI) and hierarchical linear modeling (HLM) methods for making cross-level inferences between individual-level and group-level factors in school effectiveness research. Recommends HLM when intraclass correlations are high. ATI is suitable when intraclass correlations are low, but partitioning the…

Discusses the use or misuse of statistics or probability in society. Presented are examples from opinion polling, sports, the 1970 draft lottery, and the law. Lists 18 references. (YP)

Describes the of attribute sampling to estimate characteristics of library collections and operations. The nature of statistical sampling and making a statistical inference are covered, and examples from library situations are given. Tables of determination of sample size and evaluation of results are included. (Contains six references.) (EAM)

Data analysis problems, particularly involving the likelihood of obtaining visually ambiguous graphs, pose a barrier to efforts to promote increased use of single-case evaluation by practitioners. Uses findings from an evaluation of a cognitive-behavioral intervention with adolescent sex offenders to illustrate data analysis problems. (JPS)

Examines how the wording of statistical problems affects 11-12 year old children's answers. Ninety-six children were given statistical problems on two statistical concepts (base-rate and the law of large numbers). Indicates that the children had a high level of statistical intuition and knew when to reason statistically. (CMK)