Educators who are urged to use evidence-based practices to improve instruction often end up disappointed at the results, which fall short of those touted in the research and by the What Works Clearinghouse. Stanley Pogrow explains how common strategies researchers use to demonstrate evidence of success, such as statistical significance of or…

The consistency of psychometric properties across waves of data collection provides valuable evidence that scores can be interpreted consistently. Evidence supporting the consistency of psychometric properties can come from using a longitudinal extension of item factor analysis to account for the lack of independence of observation when evaluating…

Children live complex social lives that has various aspects, including intimate friendships, peer-acceptance and bullying dynamics which is usually studied separately in research. This study aims to investigate the interplays of these three important fields by analyzing the moderating effects of number of friendships on the relation between…

A linear model is often used to find the effect of a binary treatment D on a noncontinuous outcome Y with covariates X. Particularly, a binary Y gives the popular "linear probability model (LPM)," but the linear model is untenable if X contains a continuous regressor. This raises the question: what kind of treatment effect does the…

Small sample sizes contribute to several problems in research and knowledge advancement. This conceptual replication study confirmed and extended the inflation of type II errors and confidence intervals in correlation analyses of small sample sizes common in kinesiology/exercise science. Current population data (N = 18, 230, & 464) on four…

Demographic data, such as highest level of education attained, are often assumed to be relatively free from measurement error. As part of an evaluation of an early childhood parenting intervention, 654 parents reported their highest level of education via telephone interview at baseline and self-directed questionnaire at follow-up 5.7 years later.…

Common method variance refers to the amount of uncontrolled systematic error leading to biased estimates of scale reliability and validity and to spurious covariance shared among variables due to common method and/or common source employed in survey-based researches. As the extended use of self-report questionnaires is inevitable, numerous studies…

Background: Meta-analysis refers to the statistical methods employed to combine results of several empirical studies in a topic of interest (Hedges & Olkin, 1985). Meta-analysis is often included in literature review studies to quantitatively analyze data from a collection of studies (Valentine et al., 2010). The statistical power of a…

Large-scale international achievement studies such as PISA have been widely used to study how educational inequality compares across countries. Yet the various different biases that may affect these estimates are often not considered or are poorly understood. In this paper we draw upon the total survey error framework to provide a case study of…

Ethnoracial identity refers to the racial and ethnic categories that people use to classify themselves and others. How it is measured in surveys has implications for understanding inequalities. Yet how people self-identify may not conform to the categories standardized survey questions use to measure ethnicity and race, leading to potential…

Post-instrument covariates are often included as controls in instrumental variable (IV) analyses to address a violation of the exclusion restriction. However, we show that such analyses are subject to biases unless strong assumptions hold. Using linear constant-effects models, we present asymptotic bias formulas for three estimators (with and…

This note is concerned with the benefits that can result from the use of the maximal reliability and optimal linear combination concepts in educational and psychological research. Within the widely used framework of unidimensional multi-component measuring instruments, it is demonstrated that the linear combination of their components that…

Normative studies are needed to obtain norms for comparing individuals with the reference population on relevant clinical or educational measures. Norms can be obtained in an efficient way by regressing the test score on relevant predictors, such as age and sex. When several measures are normed with the same sample, a multivariate regression-based…

Various areas of educational research are interested in the transitions between different states--or events--in sequential data, with the goal of understanding the significance of these transitions; one notable example is affect dynamics, which aims to identify important transitions between affective states. Unfortunately, several works have…

Although parallel analysis has been found to be an accurate method for determining the number of factors in many conditions with complete data, its application under missing data is limited. The existing literature recommends that, after using an appropriate multiple imputation method, researchers either apply parallel analysis to every imputed…