MacIntyre, Peter D., Emily Mackay, Jessica Ross, & Esther Abel (2017). The emerging need for methods appropriate to study dynamic systems: Individual differences in motivational dynamics. In Lourdes Ortega & ZhaoHong Han (Eds.), Complexity theory and language development: In celebration of Diane Larsen-Freeman (pp. 97-122, Chap 5). Amsterdam, Philadelphia: John Benjamins. (Link:

Abstract: There is a pressing need to develop methodology to study complex dynamic systems. In this chapter we review 12 specific methods that offer solutions to the methodological challenges presented by a dynamic approach. Specific methods include several qualitative interview designs, longitudinal cluster analysis, Q-methodology, the trajectory equifinality model, the idiodynamic method, latent growth modelling, and change point analysis. The collection of methods provides an overview of qualitative, quantitative, and mixed-methods approaches that have been applied to the study of complex dynamic systems. Each reviewed procedure has been applied to the study of motivation for language learning and demonstrates how to take account of multiple timescales, initial conditions, and dynamic stability among other issues. Even as methods are being refined, novel research findings are emerging. The lasting impact of Complexity Theory on the field of second language development depends on closing the present gap between metaphorical and/or theoretical development and specific research methods.

Peter D MacIntyre <> is in the Department of Psychology, Cape Breton University, Sydney, Nova Scotia, Canada.