Form-focused instruction and the measurement of implicit and explicit L2 knowledge
This chapter discusses the importance of designing valid tests of second language (L2) learning in order to investigate the effects of form-focused instruction (FFI). It argues that such tests must provide measures of both implicit and explicit L2 knowledge. Various methods for designing such tests are considered – the methods used in psychological studies of implicit/explicit knowledge, the methods used in neuropsychological studies, and the methods that have been used in FFI studies. Psychometric studies (Ellis, 2005; Bowles, 2011; Zhang, 2013) that have investigated attempts to design tests that distinguish the two types of knowledge are then reviewed. The chapter concludes by proposing a set of general principles that can guide the measurement of learning in FFI studies.