The employment rate of software developers has risen significantly over the last 30 years. As a result, more students are considering computer science as a potential career path. Over the last 15 years, introductory programming course (CS1) enrollment has been increasing at a much faster rate than the increase in the number of CS faculty, with no…

Assessment is a key component of education. Routine grading of students' work, however, is time consuming. Automating the grading process allows instructors to spend more of their time helping their students learn and engaging their students with more open-ended, creative activities. One way to automate grading is through computer-based…

This study explores using transfer learning in machine learning for natural language processing (NLP) to create generic automated essay scoring (AES) models, providing instant online scoring for statewide writing assessments in K-12 education. The goal is to develop an instant online scorer that is generalizable to any prompt, addressing the…

Automated assessment using Natural Language Processing (NLP) has the potential to make English speaking assessments more reliable, authentic, and accessible. Yet without careful examination, NLP may exacerbate social prejudices based on gender or native language (L1). Current NLP-based assessments are prone to such biases, yet research and…

The digital transformation in educational assessment has led to the proliferation of large-scale data, offering unprecedented opportunities to enhance language learning, and testing through machine learning (ML) techniques. Drawing on the extensive data generated by online English language assessments, this dissertation investigates the efficacy…

Vocabulary researchers have started expanding their assessment toolbox by incorporating timed tasks and psycholinguistic instruments (e.g., priming tasks) to gain insights into lexical development (e.g., Elgort, 2011; Godfroid, 2020b; Nakata & Elgort, 2020; Vandenberghe et al., 2021). These timed sensitive and implicit word measures differ…

This dissertation aims to identify the locus of L2 processing inefficiency. Previous studies suggest that non-native processing is a specific result of an inefficient predictive mechanism that limits the ability of learners to generate linguistic expectations (Gruter, Rohde, & Schafer, 2014; 2016). Thus, this study employs two distinct online…

In this dissertation, I explore unsupervised techniques for the task of automatic short answer grading. I compare a number of knowledge-based and corpus-based measures of text similarity, evaluate the effect of domain and size on the corpus-based measures, and also introduce a novel technique to improve the performance of the system by integrating…

Indirect metaphors are pervasive in everyday language: People talk about "long" vacations, "short" tempers, and "colorful" language. But, why do we use concrete lexical items that are associated with the physical world when we talk about abstract, or non-physical, concepts? A potential answer is provided by proponents…

A dialog system or a conversational agent provides a means for a human to interact with a computer system. Dialog systems use text, voice and other means to carry out conversations with humans in order to achieve some objective. Most dialog systems are created with specific objectives in mind and consist of preprogrammed conversations. The primary…