Many experimental designs in educational and behavioral research involve at least one level of clustering. Clustering affects the precision of estimators and its impact on statistics in cross-sectional studies is well known. Clustering also occurs in longitudinal designs where students that are initially grouped may be regrouped in the following…

I discuss three common practices that obfuscate or invalidate the statistical analysis of randomized controlled interventions in applied linguistics. These are (a) checking whether randomization produced groups that are balanced on a number of possibly relevant covariates, (b) using repeated measures ANOVA to analyze pretest-posttest designs, and…

The focus of this article is two-fold. First, it describes a model that can be used to guide the evaluation of teacher professional development. The model combines important components of existing models and incorporates the use of students' perceptions for examining teacher change. Second, the article reports the evaluation of a teacher…

The aim of this research is to study the accurate prediction of comparing test information and evaluation result by multidimensional computerized adaptive scholastic aptitude test program used for grade 9 students under different reviewing test conditions. Grade 9 students of the Secondary Educational Service Area Office in the North-east of…

While there has been increased scholarship in recent years on diversity in higher education, most of this research has failed to include 2-year institutions in its analyses. This study examined whether the racial composition of the community college student body is correlated with an institution's normative climate toward three diversity…

An experiment compared asynchronous versus synchronous instruction in an online quantitative course. Mann-Whitney U-tests, correlation, analysis of variance, t tests, and multivariate analysis of covariance (MANCOVA) were utilized to test the hypothesis that more high-quality online experiential learning interactions would increase grade.…

Vocabulary knowledge at school entry is a robust predictor of later reading achievement. Many children begin formal reading instruction at a significant disadvantage due to low levels of vocabulary. Until recently, relatively few research studies examined the efficacy of vocabulary interventions for children in the early primary grades (e.g.,…

This paper reports the reanalysis of data collected in a study of 3 determinants of classroom environment (viz. year level, subject, and school type) using multivariate analysis of variance and multilevel analysis. Data were collected from 2,211 students in Queensland Catholic and government schools. The Catholic School Classroom Environment…

It is a false, but common, belief that statistical significance testing evaluates result replicability. In truth, statistical significance testing reveals nothing about results replicability. Since science is based on replication of results, methods that assess replicability are important. This is particularly true when multivariate methods, which…

Although stated objectives of multivariate multiple regression and canonical correlation seem different, aspects of the analyses themselves are mathematically equivalent. A numerical example of the similarities is given, with reference to omnibus significance testing, variable weighting schemes, and dimension reduction analysis. (SLD)

Researchers have long searched for a relationship between school resources and student achievement. The search for this relationship has relied heavily on the use of education production functions. Despite years of research on this topic, there has been little agreement concerning which resources are the most essential variables to increase…

A generalized measure of association and an associated test of significance are presented for nominal independent variables in which any number or combination of interval, ordinal, or nominal dependent variables can be analyzed. A permutation test of significance is provided for the new measure. (SLD)

Repeated measures experimental designs, often referred to as "within-subjects" designs, offer researchers opportunities to study research effects while "controlling" for subjects. These designs offer greater statistical power relative to sample size. However, threats to internal validity such as carryover or practice effects…

Different ways that dependent variables can cause multivariate significance are illustrated. It is argued that univariate tests should not be used as follow-up procedures to identify the variables that can contribute to multivariate significance. Methods that can be used to determine the contributions individual variables make to multivariate…

Generalizability or invariance procedures have been known for over three decades. Through the years, these procedures have not been widely discussed or employed. One reason for the lack of use is that most of the articles on invariance procedures have been mathematically oriented. The mathematical orientation of research articles and the lack of…