Research into second language acquisition (SLA) has shown that individual difference (ID) variables can be strong predictors of language achievement (e.g., Dornyei, 2003; Skehan, 2003). Traditionally, this research conceptualized ID variables as static and monolithic variables (e.g., Dornyei, 2010). More recently scholars have questioned this…

The purpose of this mixed methods study was to understand how context may shape multiple goal negotiation. Prior research has focused on identifying variables that influence goal pursuit in general, but little attention has been given to how these principles operate in different circumstances. This study adopted the Dynamic Systems Model of…

Foreign language enrollments in U.S. higher education are falling at an unprecedented rate since the 1980s. This mixed methods case study sought to investigate this phenomenon by examining the motivational and attitudinal profiles of 89 beginning-level learners of foreign languages (Spanish, French, Arabic, Japanese) and the contextual factors…

The U.S. is growing in its recognition of the value of multilingualism, and is rapidly expanding educational programs, such as dual language immersion (DLI), to that end (Singleton et al., 2018). However, the historical socio-political, regulatory, and cultural contexts have led to a current climate that may not demonstrate equivalent value of its…

Previous literature has shown that voicing contrast is a difficult feature for Chinese-English emergent bilingual learners of L3 Spanish (Bravo Diaz, 2020; Chen, 2007; Zhang, 2022). The production of voicing contrast in stops has been broadly investigated in second and third language studies (e.g., Zampini, 1998; Llama, 2010; Wrembel, 2014), but…

Guided by Dynamic Systems Theory (DST) and multidimensional perspectives on individual differences (IDs) in instructed second language (L2) learning (e.g., Larsen-Freeman, 2014; Sun & Zhang, 2020), this longitudinal mixed-methods study focuses on three conceptually different categories of L2 learners' IDs: working memory (WM), motivation, and…

In 2015, then-Higher Education Minister Rodolfo Alarcon said in response to many Cubans' inability to communicate in the international language, English fluency would be required by students as a university exit requirement ("Mastering English," 2015).The purpose of this interpretive qualitative study was to understand the experiences of…

Drawing on theories from Applied Linguistics research, this doctoral dissertation brings together European perspectives on "language," "identity," and "voice" in an examination of English as the international language of science (EILS). Using the theoretical frame of Dynamic Systems Theory (DST), each of the chapters…

This dissertation investigates the longitudinal development of Chinese language proficiency among students in a Chinese as a Foreign Language (CFL) Flagship Program at an American public university from 2014 to 2024. Using Bayesian multilevel regression models, this study assesses the trajectories of listening, speaking, and reading proficiency…

This study explored the potential benefits and barriers of using quick response (QR) codes as a means by which to provide audio materials to middle-school students learning Spanish as a foreign language. Eleven teachers of Spanish to middle-school students created transmedia materials containing QR codes linking to audio resources. Students…

This dissertation sheds light on how learners of German, NSs of German, and Americans unfamiliar with German reach decisions about the nature of speech acts that they witness NSs of German perform in three authentic video clips. It also aims to gain a better understanding of what sources members of the three groups bring to bear when they attempt…

To date, few studies have investigated the production of linguistic complexity and accuracy with naturalistic data. Very often, the data are obtained in a laboratory or laboratory-style settings, with tasks defined by the researcher rather than the instructor (Hatch, 1978; Seedhouse, 2004). Additionally, replicability of studies that investigate…

The lack of empirical scholarship on professional development initiatives for teachers of English language learners (ELLs) in US schools has been repeatedly documented in educational research. The present dissertation project examines a professional development course specifically designed for K-12 teachers of ELLs. The course aims to foster the…

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…