When in the late 1990s we set out to review the accumulated research on second language (L2) instructional effectiveness, it was with a sense – though no certainty – that a journey into the uncharted territory of systematic research synthesis would eventually prove worth the effort. In order to find a fitting methodology, and in the absence of any guidance within applied linguistics, we willingly delved into challenging techniques and debates from other disciplines. A few years later, we had to search long and hard to find enough synthesists working on language learning and teaching issues to warrant a book, but we did, and we saw that new effort as an important, if initial, step towards the adoption and adaptation of research synthesis, and particularly the subset of methods known as meta-analysis, to the problems of applied linguistics. Now, some ten years after our first publication on the topic, applications of meta-analysis have increased dramatically in the field, as this Timeline clearly shows. For some topics (e.g. interaction, corrective feedback), we have even seen several studies replicating and building on each other. We are pleased with these developments and welcome the efforts of the field to engage in rigorous and meaningful reviews of L2 research, with an eye towards cumulative explanation of key phenomena. At the same time, we also hope that researchers will avail themselves of the full potential of systematic research synthesis, which considerably transcends the narrower domain of meta-analysis and includes other quantitative as well as qualitative methods that more fully enable the task of synthesizing accumulated knowledge in the increasingly diverse research landscape of applied linguistics.
Clearly, systematic research synthesis is a recent introduction in applied linguistics, but it has a long and influential history in the social sciences. Accordingly, we have selected key publications and events that demarcate the landscape of synthesis not only in L2 research, but also in the emergence of core methodologies from psychology, education and health. For ease of viewing, we have shaded the non-L2 entries in the Timeline. Our selection of benchmark publications and events reflects six important themes, referenced in the last column of the Timeline as follows:
A Empirical reviews subscribing to principles and techniques of synthesis, including meta-analyses (A.1), quantitative syntheses (A.2) and syntheses of qualitative research (A.3).
B Reviews that draw on features of synthesis without adhering to the basic principles of the methodology.
C Selected historical, methodological and conceptual discussions associated with the development of research synthesis.
D Selected methodological guides for conducting research syntheses.
E Disciplinary activity associated with research synthesis (e.g. new editorial policies; creation of software, journals, associations or entities devoted to synthesis).
F Discussions of epistemological tensions and expansions in research synthesis, particularly in the service of synthesizing qualitative and mixed-methods research.
As with any other field, technical and epistemological developments continuously sharpen and renew the nature of what synthesists can do and the degree of reflexivity with which they do it. We hope applied linguists, particularly new generations, will cultivate a critical excitement towards synthesis and nurture a synthetic ethic for all of their research work. This Timeline chronicles the emergence of synthesis in applied linguistics as one approach to achieving this goal.
John Norris is Associate Professor in the Department of Second Language Studies at the University of Hawai'i at Mānoa, USA, where he conducts research and teaches courses on second and foreign language assessment, evaluation, pedagogy and research methods. Recent books include Toward useful program evaluation in college foreign language education (co-edited with John McE. Davis, Castle Sinicrope and Yukiko Watanabe; National Foreign Language Resource Center, 2009), Task-based language teaching: A reader (co-editor with Kris Van den Branden and Martin Bygate; John Benjamins, 2009) and Validity evaluation in language assessment (Peter Lang, 2008).
Lourdes Ortega is Professor in the Department of Second Language Studies at the University of Hawai'i at Mānoa, USA, and Editor of Language Learning. Her research is in the areas of second language acquisition and instruction, L2 writing and research methods. Recent books are The longitudinal study of advanced L2 capacities (co-edited with Heidi Byrnes; Routledge, 2008) and Understanding second language acquisition (Hodder, 2009).
