Dissertation Defense: Young-A Son

Candidate Name: Young-A Son

Major: Linguistics

Advisor: Lourdes Ortega, Ph.D.

Title: Measuring Heritage Language Learners’ Proficiency for Research Purposes: An Argument-Based Validity Study of the Korean C-Test

Heritage language learners (HLLs) have increasingly become a focus of interest in applied linguistics research (Kagan & Dillon, 2012), but the lack of consistent conceptualization of HL proficiency has hindered the systematic accumulation of research knowledge about HLLs (Son, 2017). Shortcut proficiency measures may be a way to address these shortcomings (Norris, 2018). C-tests have been found to be particularly promising in providing a quick measurement of language learners’ global proficiency (Eckes & Grotjahn, 2006), yet validation studies on this shortcut measure have focused on Foreign Language Learners (FLLs).

To address these critical gaps, this study developed a validity argument (Kane 2006, 2011, 2013) to evaluate the use of an innovative Korean C-test (Son et al., 2018) to assess Korean HLLs and FLLs for applied linguistics research purposes. Ninety-three Korean language learners, 41 HLLs and 52 FLLs, were assessed using five instruments: the Korean C-test, an Elicited Imitation Test (EIT, Kim et al., 2016), ACTFL Oral Proficiency Interview-computer (OPIc), ACTFL Writing Proficiency test (WPT), and a self-assessment questionnaire.The resulting data were then examined for five inferences—theoretical grounds, evaluation, generalization, explanation, and extrapolation—in terms of warrants, assumptions, backing, and rebuttals.

C-test items accurately and reliably distributed Korean learners into a wide range of proficiency levels (IRT person separation index=5.50 and Cronbach’s α=.94). Although C-test performance was closely related to the literacy-based WPT proficiency indicator (ρ=.87), it also correlated strongly with the oracy-based OPIc and EIT proficiency measures (ρ=.81 or higher). Multiple regression analyses showed that both speaking and writing proficiency could explain 80% of the C-test score variance with R2 = .80, F (2,90) = 181.83, ρ = .000. Nevertheless, writing was more important than speaking proficiency in predicting C-test performance for HLLs, whereas both language skill predictors were equally important for FLLs. Furthermore, a hierarchical cluster analysis provided a bottom-up categorization of learners into HLLs and

FLLs and questioned the expectation that HLLs are always linguistically different to FLLs. Overall, the evidence supported the use of the Korean C-test to assess both HLLs and FLLs across a range of proficiency levels for applied linguistic research purposes. The study concludes with suggestions for future research.

Monday, September 24 at 2:00pm to 4:00pm

Poulton Hall, 230
1421 37th St., N.W., Washington

Event Type

Academic Events, Dissertation Defense


Georgetown College, Linguistics, Graduate School of Arts and Sciences



Open to the public and the press?


Event Contact Name

Benjamin Croner

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