The implicit/ explicit distinction is central to our understanding of the nature of L2 acquisition. This book begins with an account of how this distinction applies to L2 learning, knowledge and instruction. It then reports a series of studies describing the development of a battery of tests providing relatively discrete measurements of L2 explicit/ implicit knowledge. These tests were then utilized to examine a number of key issues in SLA - the learning difficulty of different grammatical structures, the role of L2 implicit/ explicit knowledge in language proficiency, the relationship between learning experiences and learners' language knowledge profiles, the metalinguistic knowledge of teacher trainees and the effects of different types of form-focused instruction on L2 acquisition. The book concludes with a consideration of how the tests can be further developed and applied in the study of L2 acquisition.

Testing of second language pragmatics has grown as a research area but still suffers from a tension between construct coverage and practicality. In this book, the authors describe the development and validation of a web-based test of second language pragmatics for learners of English. The test has a sociopragmatic orientation and strives for a broad coverage of the construct by assessing learners' metapragmatic judgments as well as their ability to co-construct discourse. To ensure practicality, the test is delivered online and is scored partially automatically and partially by human raters. We used the argument-based approach to validation, which showed that the test can support low-stakes decisions about learners' knowledge of sociopragmatics in English.