This paper follows an earlier report of young children's object play activities investigated in a cross-sectional sample of 289 typically developing children. Thirty-minute videotaped observations were taken of children at 8, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months of age in their homes. Forty-nine percent were boys. Children were identified…

Item factor analysis (IFA), also known as Multidimensional Item Response Theory (MIRT), is a general framework for specifying the functional relationship between a respondent's multiple latent traits and their response to assessment items. The key element in MIRT is the relationship between the items and the latent traits, so-called item factor…

Background: Counts are familiar outcomes in education research settings, including those involving tests of interventions. Clustered data commonly occur in education research studies, given that data are often collected from students within classrooms or schools. There is a wide array of distributions and models that can be used for clustered…

In order to investigate the influence of separation of grade distributions and ratio of common items on the precision of vertical scaling, this simulation study chooses common item design and first grade as base grade. There are four grades with 1,000 students each to take part in a test which has 100 items. Monte Carlo simulation method is used…

This study investigated the extent to which class-specific parameter estimates are biased by the within-class normality assumption in nonnormal growth mixture modeling (GMM). Monte Carlo simulations for nonnormal GMM were conducted to analyze and compare two strategies for obtaining unbiased parameter estimates: relaxing the within-class normality…

Analysts of discrete data often face the challenge of managing the tendency of inflation on certain values. When treated improperly, such phenomenon may lead to biased estimates and incorrect inferences. This study extends the existing literature on single-value inflated models and develops a general framework to handle variables with more than…

Despite broad applications of growth curve models, few studies have dealt with a practical issue -- nonnormality of data. Previous studies have used Student's "t" distributions to remedy the nonnormal problems. In this study, robust distributional growth curve models are proposed from a semiparametric Bayesian perspective, in which…

Growth curve models are widely used in social and behavioral sciences. However, typical growth curve models often assume that the errors are normally distributed although non-normal data may be even more common than normal data. In order to avoid possible statistical inference problems in blindly assuming normality, a general Bayesian framework is…

Nonnormality of univariate data has been extensively examined previously (Blanca et al., 2013; Micceri, 1989). However, less is known of the potential nonnormality of multivariate data although multivariate analysis is commonly used in psychological and educational research. Using univariate and multivariate skewness and kurtosis as measures of…

Growth curve modeling provides a general framework for analyzing longitudinal data from social, behavioral, and educational sciences. Bayesian methods have been used to estimate growth curve models, in which priors need to be specified for unknown parameters. For the covariance parameter matrix, the inverse Wishart prior is most commonly used due…

This research provides new evidence on the political activity and policy-setting agenda of the largest national teachers' union during a time of political change. Using a longitudinal dataset comprised of election outcomes and campaign contributions for all candidates for federal office and the National Education Association's (NEA) official…

Teacher churning likely harms student achievement. However, the phenomenon of within-school grade-level teacher reassignments is understudied. The current study provides descriptive evidence on the frequency and predictors of within-school teacher grade switching using both longitudinal administrative data from Michigan and nationally…

Using 1972-2000 data from the Consumer Expenditure Survey (CES), a nationally representative survey of spending conducted by the Bureau of Labor Statistics, this paper investigates changes in the income-based gap in monetary investments in children under the age of six, when most children typically have entered school in the United States. The…

This 2016 Enrollment Report was prepared for the State Board of Higher Education by the North Dakota University System (NDUS). Enrollment trends highlighted herein include a one-year comparison for two-year institutions, four-year institutions, and system wide. Trends over the last five years and the last ten years are also described. For example,…

It is common to assume that worker productivity is normally distributed, but this assumption is rarely if ever tested. We estimate the distribution of worker productivity where individual productivity is measured with error, using the productivity of elementary school teachers as an example. Proposals to improve teacher productivity often focus on…