Articles Introduction to the Special Issue on Themes in SLA Research Kathleen Bardovi-Harlig and Zoltán Dörnyei 1–2 Input, Interaction and Output: An Overview Susan M. Gass and Alison Mackey 3–17 Researching the Effects of Form-Focussed Instruction on L2 Acquisition Rod Ellis 18–41 Individual differences in second language acquisition Zoltán Dörnyei 42–68 Interlanguage Development: Main Routes and Individual Paths Kathleen Bardovi-Harlig 69–82 Beyond Repair: Conversation Analysis as an Approach to SLA Gabriele Kasper 83–99 Cognitive Perspectives on SLA: The Associative-Cognitive CREED Nick C. Ellis 100–121