An interdisciplinary field: theoretical approaches in SLA
The field of SLA investigates the acquisition of an additional language after the first language or languages have been already learned in life. As such, it seeks to explain human language development by older children, adolescents, and adults across a wide variety of naturalistic, instructed, and mixed contexts. With a history extending over half a century that has been acquisition, SLA continues to be a most porous and interdisciplinary field. Today, it harbours a notable diversity of epistemological approaches. Four theoretical approaches showed tremendous vitality by the close of the twentieth century: cognitive-interactionist, formal linguistic, Vygotskian sociocultural, and usage-based emergentist SLA. SLA in the twenty-first century exhibits novel intellectual influences spurred by the social turn and by new interdisciplinary connections with bilingualism, psycholinguistics, education, anthropology, and sociology. These newer influences have led to the crafting of SLA theories that offer a social re-specification of many SLA interests. (Ortega, 2011: 181. In Simpson (ed)).
Chapelle, C., & Duff, P. (2003). Some Guidelines for Conducting Quantitative and Qualitative Research in TESOL. TESOL Quarterly, 37(1), 157-178.
Lazaraton, A. (2003). Evaluative Criteria for Qualitative Research in Applied Linguistics: Whose Criteria and Whose Research? Modern Language Journal,87(1), 1-12.
Marsden, E., Mackey A., & Plonsky, L. (2016). The IRIS Repository: Advancing research practice and methodology. In A. Mackey & E. Marsden (Eds.), Advancing methodology and practice: The IRIS Repository of Instruments for Research into Second Languages (pp. 1-21). New York: Routledge.
Purpura, J. E., Brown, J. D., & Schoonen, R. (2015). Improving the validity of quantitative measures in applied linguistics research. Language Learning, 65, 37–75. doi:10.1111/lang.12112
Riazi, M. (2016). The Routledge encyclopedia of research methods in applied linguistics. London: Routledge.
Riazi, A., & Candlin, C. (2014). Mixed-methods research in language teaching and learning: Opportunities, issues and challenges. Language Teaching, 47(2), 135-173.
Simpson, J. (Ed.). (2011). The Routledge handbook of applied linguistics. Taylor & Francis.