This landmark volume offers a collection of conceptual papers and data-based research studies that investigate the dynamics of language learning motivation from a complex dynamic systems perspective. The chapters seek to answer the question of how we can understand motivation if we perceive it as a continuously changing and evolving entity rather than a fixed learner trait. From the contents: 6. Ema Ushioda: Context and Complex Dynamic Systems Theory. 18. Tomoko Yashima and Kumiko Arano: Understanding EFL Learners' Motivational Dynamics: A Three-Level Model from a Dynamic System and Sociocultural Perspective. 21. Ryo Nitta and Kyoko Baba: Self-Regulation in the Evolution of the Ideal L2 Self: A Complex Dynamic Approach to the L2 Motivational Self System.