This book investigates the effects of corpus work on the process of foreign language learning in ESP settings. It suggests that observing learners at work with corpus data can stimulate discussion and re-thinking of the pedagogical implications of both the theoretical and empirical aspects of corpus linguistics. The ideas presented here are developed from the Data-Driven Learning approach introduced by Tim Johns in the early nineties. The experience of watching students perform corpus analysis provides the basis for the two main observations in the book: a) corpus work provides students with a useful source of information about ESP language features, b) the process of search-and-discovery implied in the method of corpus analysis may facilitate language learning and promote autonomy in learning language use. The discussion is carried out on the basis of a series of corpus-based explorations by students and provides suggestions for developing new tasks and tools for language learners.