Towards a more nuanced understanding of the interface between explicit and implicit knowledge in SLA

Proficient second language users display an impressive command of the target language, which rests on a foundation of explicit and implicit linguistic knowledge. This distinction between explicit (verbalizable, rule-based) and implicit (tacit, intuitive) knowledge is foundational to a cognitive understanding of (second) language acquisition. As such, it has propelled a great deal of theoretical and empirical work in SLA and cognitive psychology. In this plenary talk, I present an overview of theoretical and empirical advances in research on implicit and explicit knowledge in second language research, with the goal to highlight how this body of work may benefit many subdisciplines across SLA. 

The SLA literature has been replete with calls for better measures of implicit knowledge. In response to this need, a line of interconnected test validation studies, dating back to Ellis's seminal research (Ellis, 2005), has confirmed the promise of reaction-time-based tasks (e.g., word monitoring) and time-pressured language tasks (e.g., elicited imitation) as valid and reliable measures of implicit linguistic knowledge (for an empirical synthesis, see Godfroid & Kim, 2021). At the same time, questions remain, notably regarding the distinction between implicit and automatized explicit knowledge at a practical (as opposed to theoretical) level (Godfroid et al., in prep.). 

Equipped with better and more valid measures, SLA researchers have begun to revisit long-standing questions in SLA, for instance: How do explicit and especially implicit knowledge of language develop longitudinally over time (Kim & Godfroid, under review)? And do the two types of knowledge interact directly, or "interface", in the learner's mind (Godfroid, in press)? This work highlights how our understanding of the "interface hypothesis" has evolved since Krashen's early writings (e.g., Krashen, 1981). Indeed, I argue that the interface question is best reconceptualized as a more fine-grained set of empirically tractable questions regarding the relationship between explicit/implicit instruction, processing, and knowledge (Godfroid, in press). The findings have implications for psycholinguistics, instructed second language acquisition, vocabulary research, and speaking and writing research, among others, and may ultimately help illuminate different paths to achieving second language proficiency.

References

Ellis, R. (2005). Measuring implicit and explicit knowledge of a second language: A psychometric study. Studies in Second Language Acquisition, 27(2), 141-172. 

Godfroid, A. (in press, 2022). Hypotheses about the interface between explicit and implicit knowledge in SLA. In A. Godfroid and H. Hopp (Eds.), The Routledge Handbook of Second Language Acquisition and Psycholinguistics. Routledge.

Godfroid, A., & Kim, K. M. (2021). The contributions of implicit-statistical learning aptitude to implicit second language knowledge. Studies in Second Language Acquisition, 43(3), 606-634. 

Godfroid, A., Kim, K., Hui, B., & Isbell, D. (in preparation). Synthesizing research on implicit, automatized explicit, and explicit L2 knowledge: An empirical extension.

Krashen, S. D. (1981). Second language acquisition and second language learning. University of Southern California.