Confidence intervals are an important tool to indicate uncertainty of estimates and to give an idea of probable values of an estimate if a different sample from the population was drawn or a different sample of measures was used. Standard symmetric confidence intervals for proportion estimates based on a normal approximation can yield bounds…

P. A. Frazier, A. P. Tix, and K. E. Barron (2004) highlighted a normal theory method popularized by R. M. Baron and D. A. Kenny (1986) for testing the statistical significance of indirect effects (i.e., mediator variables) in multiple regression contexts. However, simulation studies suggest that this method lacks statistical power relative to some…

This article integrates research on minority influence and information sampling in groups. The traditional information-sampling paradigm implies that the discussion bias for common over unique information affects all types of groups universally. We proposed an alternative in which information sampling depends on the composition of opinions. We…

A structural equation modeling approach to scale reliability evaluation can be employed to estimate generalizability theory indexes in settings where sampling of subjects and conditions is carried out. In one- and two-facet crossed designs, it is demonstrated how this method can be used to obtain estimates of relative generalizability…

Using longitudinal data from the National Survey on Child and Adolescent Well-Being (NSCAW), this study investigates entry into intensive or restrictive settings during a 36-month study period. Specifically, this analysis examines entry into treatment foster care, group homes, residential treatment, and inpatient psychiatric care for youth placed…

Two recent simulation studies were conducted to aid in the diagnosis and interpretation of equating differences found between random and matched (nonrandom) samples for four commonly used equating procedures: (1) Tucker; (2) Levine equally reliable; (3) Chained equipercentile observed-score; and (4) three-parameter, item response theory true-score…

Standard statistical methods are used to analyze data that is assumed to be collected using a simple random sampling scheme. These methods, however, tend to underestimate variance when the data is collected with a cluster design, which is often found in educational survey research. The purposes of this paper are to demonstrate how a cluster design…

Model-based methods for estimating the population mean in stratified clustered sampling are described. The importance of adjusting the weights is assessed by an approach considering the sampling variation of the adjusted weights and its (variance) components. The resulting estimators are more efficient than the jackknife estimators for a variety…

The popularity of the sample survey in educational research makes it necessary for consumers to tell a good study from a poor one. Several sources were identified that gave advice on how to evaluate a sample design. The sources are either limited or too extensive to use in a practical sense. The purpose of this paper is to recommend six important…

Some years ago, B. Efron and his colleagues developed bootstrap resampling methods as a way of estimating the degree to which statistical results will replicate across variations in sample. A basic problem in the multivariate use of bootstrap procedures involves the requirement that the results across resamplings must be rotated to best fit in a…

This paper empirically and systematically assessed the performance of bootstrap resampling procedure as it was applied to a regression model. Parameter estimates from Monte Carlo experiments (repeated sampling from population) and bootstrap experiments (repeated resampling from one original bootstrap sample) were generated and compared. Sample…

The empirical Bayes modeling approach--latent ability random sampling in the item response theory (IRT) context--to the IRT modeling of psychological tests is described. Under the usual empirical Bayes unidimensional IRT modeling approach, the posterior distribution of examinee ability given test response is approximately normal for a long test.…

Large sample standard errors for the Tucker method of linear equating under the common item nonrandom groups design are derived under normality assumptions as well as under less restrictive assumptions. Standard errors of Tucker equating are estimated using the bootstrap method described by Efron. The results from different methods are compared…

In applied and experimental research, it has been demonstrated that the extreme groups procedure is more powerful than the standard correlational approach for some values of the correlation and extreme group size. Methods are provided for using the covariance information that is usually discarded in the classical extreme groups approach.…

Assesses conditional states of item mastery found among items from different item domains and the effectiveness of various procedures for identifying such conditional relations. Item domains considered were from the curriculum area of multiplication of whole numbers, and were defined by a domain referenced testing system. (Author/RC)