Although decades of research attest to the importance of vocabulary teaching and learning, and recent research points to principles of effective vocabulary instruction, the small number of studies on actual classroom practice suggest that teachers continue to use the least effective approaches, often focusing on memorization of definitions.…

When acquiring a second language, learners must become able to perceive the difference between novel sounds ("discrimination") and also associate strings of sounds with distinct vocabulary items ("lexical encoding"). Recent research has questioned whether discrimination is a sufficient or necessary condition for encoding, and…

Enabling learners to successfully use their second language (L2) in meaningful ways is a critical goal of instruction. Ultimately, most learners want to meet the L2 demands of the contexts in which they will use the language. To accomplish this, learners must develop linguistic knowledge and apply it in a manner that is contextually appropriate…

This dissertation presents various machine learning applications for predicting different cognitive states of students while they are using a vocabulary tutoring system, DSCoVAR. We conduct four studies, each of which includes a comprehensive analysis of behavioral and linguistic data and provides data-driven evidence for designing personalized…

This dissertation consists of three studies that investigate the extent to which speakers and listeners can and do plan ahead during production and comprehension. Study 1 investigates the attentional requirements of word selection. In two dual-task experiments, subjects categorized tones and then named pictures while word selection difficulty was…

Second language (L2) learners of tone languages do not perceive and produce the different tones of the target language with equal ease. The most common explanation for these asymmetries is that acoustically salient tones are the easiest to learn. An alternative explanation is that tones are easiest to learn when they are highly frequent in the…

Studies of connected speech have repeatedly shown that the contextual predictability of a word is related to its phonetic duration; more predictable words tend to be produced with shorter duration, when other factors are controlled for (Aylett & Turk, 2004, 2006; Bell et al., 2003; Bell, Brenier, Gregory, Girand, & Jurafsky, 2009; Gahl,…

The purpose of this study was to determine the effectiveness of three researcher-designed experimental models of vocabulary instruction during shared storybook read alouds on kindergarten children's Tier Two target word learning and maintenance of word knowledge. The Integrated Model consisted of two readings of the same storybook, direct…

Preschool teachers' literacy instruction during classroom activity is important to young children's early development of literacy skills. The present study employed repeated measure ANOVAs to examine the dimensions of 42 Head Start teachers' literacy instruction (i.e., literacy content, teaching process, and lexical characteristics) during large…

The purpose of this mixed-methods study was to examine the impact of Web multimodality plus dialogical interactions in the acquisition and retention of novel lexical items among EFL students under a social constructionist framework. The lexical acquisition of 107 1st-year English majors at the University of Costa Rica was analyzed through…

Students who are deaf and use sign language frequently have language delays that affect their literacy skills. Students who use American Sign Language (ASL) often lack fluent language models in both the home and school settings, delaying both the development of a first language and the development of literacy in printed English. Mediated and…

America's adult populace has failed to keep pace with the rapid inundation of science-centric advancements affecting nearly every facet of personal and public life. With deficiencies in areas of science knowledge, America's adult populace is characterized as civic science illiterate. This research constructed and employed the renewed citizen…

The goal of this dissertation is to introduce a method for deriving morphemes from Arabic words using stem patterns, a feature of Arabic morphology. The motivations are three-fold: modeling with morphemes rather than words should help address the out-of-vocabulary problem; working with stem patterns should prove to be a cross-dialectally valid…

This study employed Bachman and Palmer's (2010) Assessment Use Argument framework to investigate to what extent the use of a second language oral test as an exit test in a Hong Kong university can be justified. It also aimed to help test developers of this oral test identify the most critical areas in the current test design that might need…

This study investigated the longitudinal development of L2 vocabulary by 17 individual adult L2 learners in an English as a second language (ESL) instructed context over one academic year, combining a longitudinal case study design with two cross-sectional comparisons in order to enhance (a) detailed documentation addressing the idiosyncrasy of L2…