Questionnaires in Second Language Research is the first state-of-the-art methodological guide for producing and using questionnaires as reliable and valid research instruments in second language studies. Zoltán Dörnyei and Jean-Marc Dewaele provide a comprehensive, reader-friendly overview of the theory of questionnaire design, administration, and processing, made accessible with a detailed how-to guide and concrete, real-life applications.This new edition is thoroughly updated to reflect developments in the field and with recent example studies that focus on considerations, challenges, and opportunities raised at all stages of the research process by online questionnaires. There is also expanded, detailed guidance on how to use the IRIS database and how to clean, process, and analyze questionnaire data prior to determining and reporting findings.This is an invaluable resource to students and researchers of SLA, applied linguistics, psychology, and education who are interested in understanding and conducting quantitative L2 research using questionnaires and surveys.