How do educators and parents determine when to offer and when to withhold guidance to best support learners? For centuries, this question has been at the heart of a fundamental inquiry for educators and researchers. Seeking to answer this question, this book presents a study of the impact of different timings of pedagogical intervention in second / foreign language education. In a set of comprehensible narratives, the author reviews a wide range of literature including the recent history of language teaching practices, cognitive psychology and neuroscience.The detailed descriptions of the preliminary studies leading to the main study show the process of identifying the problematic features for particular learner demographics, the composition and the selection of language-learning tasks, test material construction among other essential ellements for carrying out an empirical study. The research methods are tightly constrained producing clear outcomes both in qualitative and quantitative inquiries. The book provides original and practical information with illustrative examples for any language educator, researcher, or doctoral student.