Developing qualitative longitudinal case studies of advanced language learners

As Yin (2003, p. xiii) notes, case study methodology has often been considered a “weak sibling” among social science research methods. Yet, longitudinal case studies are among the earliest and most enduring forms of first and second language acquisition research. Case studies have proven to be both empirically rich and theoretically generative in studies of second language acquisition (SLA). In fact, in a recent review of case study research in SLA, van Lier (2005) asserts that case studies have “helped to shape the entire field in quite substantial ways” (p. 198).