In contemporary methodological thinking, replication holds a central place. However, relatively little attention has been paid to replication in the context of complex dynamic systems theory (CDST), perhaps due to uncertainty regarding the epistemology-methodology match between these domains. In this paper, we explore the place of replication in…

A quarter of a century has passed since complex dynamic systems theory was proposed as an alternative paradigm to rethink and reexamine some of the main questions and phenomena in applied linguistics and language learning. In this article, we report a scoping review of the heterogenous body of research adopting this framework. We analyzed 158…

Complex Dynamic Systems Theory (CDST), an instantiation in applied linguistics of complexity epistemology that transcends disciplinary boundaries, has gained much traction and momentum over the last decade, finding expressions in a fast-growing number of empirical second language developmental studies. However, the literature, while rapidly…

Identifying changing patterns of stability and variability is crucial when examining second language development (SLD) from a complex dynamic systems theory (CDST) perspective (Larsen-Freeman, 2020). By studying attractor states, or recurrent patterns of stability, light can be shed on the underlying dynamics of a complex dynamic system (van Geert…

Second language development can be viewed as a complex and dynamic process in which learners follow non-linear trajectories and develop their language over a period of time (Larsen-Freeman, 2006). Intrinsic to the view of Complex Dynamic Systems Theory (CDST), a system is composed of hierarchical, interdependent subcomponents (learner, learner…

The launching of The Journal for the Psychology of Language Learning is a signal achievement. I begin this commentary by speculating on why it is that the Psychology of Language Learning (PLL) has enjoyed such vigor of late. I expect that one reason is the coming together of a critical mass of researchers and strong leaders over their shared…

James P. Lantolf is George and Jane Greer Professor Emeritus of Language Acquisition and Applied Linguistics and former director of the Center for Advanced Language Proficiency Education and Research at the Pennsylvania State University, USA. He is currently Adjunct Professor of Applied Linguistics in the same academic unit at Xi'an Jiaotong…

In this article, we introduce a template of methodological considerations, termed "the dynamic ensemble," for scholars doing or evaluating empirical second language development (SLD) research within a complexity/dynamic systems theory (CDST) framework. Given that CDST principles have yielded significant insight into SLD and have become…

This volume is both a state-of-the-art display of current thinking on second language development as a complex system. It is also a tribute to Diane Larsen-Freeman for her decades of intellectual leadership in the academic disciplines of applied linguistics and second language acquisition. The chapters therein range from theoretical expositions to…

In this contribution, some of the basic characteristics of complex adaptive systems, collectively labeled Dynamic Systems Theory (DST), are discussed. Such systems are self-organizing, dependent on initial conditions, sometimes chaotic, and they show emergent properties. The focus in DST is on development over time. Language is seen as a dynamic…