This dissertation examines the effectiveness of machine learning algorithms and feature engineering techniques for analyzing process data and predicting test performance. The study compares three classification approaches and identifies item-specific process features that are highly predictive of student performance. The findings suggest that…

Categorical data become increasingly ubiquitous in the modern big data era. In this dissertation, we propose novel statistical learning and inference methods for large-scale categorical data, focusing on latent variable models and their applications to psychometrics. In psychometric assessments, the subjects' underlying aptitude often cannot be…

Foreign language placement testing, an important component in university foreign language programs, has received considerable, but not copious, attention over the years in second language (L2) testing research (Norris, 2004), and it has been mostly concentrated on L2 English. In contrast to validation research on L2 English placement testing, the…

The purpose of this study was to develop a core HIV/AIDS knowledge assessment (CHAKA) for students enrolled in counseling-related degree programs. Although there are studies that examined counseling HIV/AIDS knowledge, the instruments that were used were limited in ways that may compromise the accuracy of the inferences that were made. This study…

The purpose of this study was to investigate the effect of complex structure on dimensionality assessment in compensatory and noncompensatory multidimensional item response models (MIRT) of assessment data using dimensionality assessment procedures based on conditional covariances (i.e., DETECT) and a factor analytical approach (i.e., NOHARM). …

The presence of outlying anchor items is an issue faced by many testing agencies. The decision to retain or remove an item is a difficult one, especially when the content representation of the anchor set becomes questionable by item removal decisions. Additionally, the reason for the aberrancy is not always clear, and if the performance of the…

This dissertation comprises three papers that propose, discuss, and illustrate models to make improved inferences about research questions regarding student achievement in education. Addressing the types of questions common in educational research today requires three different "extensions" to traditional educational assessment: (1)…

This dissertation research examined the changes in item RIT calibration that occurred when adding audio to a set of currently calibrated RIT items and then placing these new items as field test items in the modified assessments on the NWEA MAP test platform. The researcher used test results from over 600 students in the Poway School District in…

The increased use of polytomous item formats has led assessment developers to pay greater attention to the detection of differential item functioning (DIF) in these items. DIF occurs when an item performs differently for two contrasting groups of respondents (e.g., males versus females) after controlling for differences in the abilities of the…