This study examined the role of family-related (mother's education, depressive symptoms and child's gender) and kindergarten-related (teacher's experience, teaching practices and class size) factors in mothers' and teachers' mutual trust in Estonia and Finland. Six hundred eighteen (206 Estonian and 412 Finnish) mothers of kindergarten children…

In this paper, we document a study that involved applying a multiple imputation technique with chained equations to data drawn from the 2007 iteration of the TIMSS database. More precisely, we imputed missing variables contained in the student background datafile for Tunisia (one of the TIMSS 2007 participating countries), by using Van Buuren,…

Introduction: The reliability, minimal detectable change (MDC), and construct validity of the evidence-based practice confidence (EPIC) scale were evaluated among physical therapists (PTs) in clinical practice. Methods: A longitudinal mail survey was conducted. Internal consistency and test-retest reliability were estimated using Cronbach's alpha…

In two studies (ns = 312 and 1,149) with 9- to 12-grade students in pre-International Baccalaureate (IB) and IB Diploma programs, we evaluated the reliability, factor structure, measurement invariance, and criterion-related validity of the scores from the School Attitude Assessment Survey-Revised (SAAS-R). Reliabilities of the five SAAS-R subscale…

This chapter addresses the psychometric challenges in assessing English language learners (ELLs) and students with disabilities (SWDs). The first section addresses some general considerations in the assessment of ELLs and SWDs, including the prevalence of ELLs and SWDs in the student population, federal and state legislation that requires the…

In two studies (ns = 312 and 1149) with 9-12 grade students in pre-International Baccalaureate (IB) and IB Diploma programs, we evaluated the reliability, factor structure, measurement invariance, and criterion-related validity of the scores from the School Attitude Assessment Survey-Revised (SAAS-R; McCoach & Siegle, 2003a). Reliabilities of…

Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This seventh installment of "Explorations in Statistics" explores regression, a technique that estimates the nature of the relationship between two things for which we may only surmise a mechanistic or predictive…

This simulation study examined the performance of the curve-of-factors model (COFM) when autocorrelation and growth processes were present in the first-level factor structure. In addition to the standard curve-of factors growth model, 2 new models were examined: one COFM that included a first-order autoregressive autocorrelation parameter, and a…

Missing information is a ubiquitous aspect of data analysis, including responses to items on cognitive and affective instruments. Although the broader statistical literature describes missing data methods, relatively little work has focused on this issue in the context of differential item functioning (DIF) detection. Such prior research has…

Systematic errors are often unavoidable in the introductory physics laboratory. As has been demonstrated in many papers in this journal, such errors can present a fundamental problem for data analysis, particularly when comparing the data to a given model. In this paper I give three examples in which my students use popular curve-fitting software…

This paper studies changes of standard errors (SE) of the normal-distribution-based maximum likelihood estimates (MLE) for confirmatory factor models as model parameters vary. Using logical analysis, simplified formulas and numerical verification, monotonic relationships between SEs and factor loadings as well as unique variances are found.…

In recent years, demand for performance assessments has continued to grow. However, performance assessments are notorious for lower reliability, and in particular, low reliability resulting from task specificity. Since reliability analyses typically treat the performance tasks as randomly sampled from an infinite universe of tasks, these estimates…

Tests of the equality of variances are sometimes used on their own to compare variability across groups of experimental or non-experimental conditions but they are most often used alongside other methods to support assumptions made about variances. A new nonparametric test of equality of variances is described and compared to current "gold…

Confidence interval estimation is a fundamental technique in statistical inference. Margin of error is used to delimit the error in estimation. Dispelling misinterpretations that teachers and students give to these terms is important. In this note, we give examples of the confusion that can arise in regard to confidence interval estimation and…

This paper addresses the determination of statistically desirable response rates in students' surveys, with emphasis on assessing the effect of underlying variability in the student evaluation of teaching (SET). We discuss factors affecting the determination of adequate response rates and highlight challenges caused by non-response and lack of…