When using multiple regression for prediction purposes, the issue of minimum required sample size often needs to be addressed. Using a Monte Carlo simulation, models with varying numbers of independent variables were examined and minimum sample sizes were determined for multiple scenarios at each number of independent variables. The scenarios…

The extreme interval values and statistics (expected value, median, mode, standard deviation, and coefficient of variation) for the smallest (min) and largest (max) values of exponentially distributed variables with parameter ? = 1 are examined for different observation (sample) sizes. An extreme interval value g[subscript a] is defined as a…

This article examines theoretical and empirical issues related to the statistical power of impact estimates under clustered regression discontinuity (RD) designs. The theory is grounded in the causal inference and hierarchical linear modeling literature, and the empirical work focuses on common designs used in education research to test…

Studies designed to evaluate HIV and STD prevention interventions often involve random assignment of groups such as neighborhoods or communities to study conditions (e.g., to intervention or control). Investigators who design group-randomized trials (GRTs) must take the expected intraclass correlation coefficient (ICC) into account in sample size…

Prediction effect sizes such as ROC area are important for demonstrating a risk assessment's generalizability and utility. How a study defines recidivism might affect predictive accuracy. Nonrecidivism is problematic when predicting specialized violence (e.g., domestic violence). The present study cross-validates the ability of the Ontario…

Differential item functioning (DIF) occurs when an item on a test or questionnaire has different measurement properties for 1 group of people versus another, irrespective of mean differences on the construct. This study focuses on the use of multiple-indicator multiple-cause (MIMIC) structural equation models for DIF testing, parameterized as item…

The authors examined the robustness of multilevel linear growth curve modeling to misspecification of an autoregressive moving average process. As previous research has shown (J. Ferron, R. Dailey, & Q. Yi, 2002; O. Kwok, S. G. West, & S. B. Green, 2007; S. Sivo, X. Fan, & L. Witta, 2005), estimates of the fixed effects were unbiased, and Type I…

The current research was conducted using a quasi-experimental method and a sample of 456 incoming college students at a selective, mid-western Protestant, evangelical liberal arts college. The treatment group consisted of 215 incoming students who choose to participate in an optional ABOP prior to the beginning of regular orientation. The control…

The purpose of this study was to determine the relationship between Collective Teacher Efficacy and minority student achievement gap over and above that explained by socioeconomics, school size, and prior achievement gaps for Black and Hispanic students with White students. Forty-seven Virginia middle schools were selected to participate in the…

The longitudinal study of the 2005-06 preschool in Wake County Public School System (WCPSS) found short-term gains during the preschool year, but limited impact by kindergarten and no average impact by the end of 3rd grade on achievement, retention rates, special education placements, or attendance. Small sample sizes limit conclusions that can be…

This study evaluated the effectiveness of the HOPE program. Participants included 120 Chinese new immigrant parents with preschool children in Hong Kong from 13 preschools which were randomized into intervention group (HOPE) and comparison group (6-session parent education program). Parent participants completed measures on child behavior,…

The accuracy of item parameter estimates in the multidimensional item response theory (MIRT) model context is one that has not been researched in great detail. This study examines the ability of two confirmatory factor analysis models specifically for dichotomous data to properly estimate item parameters using common formulae for converting factor…

Cognitive theory suggests more interaction in learning environments leads to improved learning outcomes and increased student satisfaction, two indicators of success useful to program administrators. Using a sample of 359 lower-level online, undergraduate business courses, we investigated course enrollments, student and faculty time spent in…

In this paper, contemporary literature on strategy in education is examined in an integrative and analytical manner. To achieve this, an empirical investigation on strategy in education was undertaken. As the goal is to understand and propose specific research directions, the findings are both descriptive and analytical. Initially, peer reviewed…

Exploratory factor analysis (EFA) is generally regarded as a technique for large sample sizes ("N"), with N = 50 as a reasonable absolute minimum. This study offers a comprehensive overview of the conditions in which EFA can yield good quality results for "N" below 50. Simulations were carried out to estimate the minimum required "N" for different…