Brian Paltridge & Aek Phakiti 
Research Methods in Applied Linguistics [PDF ebook] 
A Practical Resource

Research Methods in Applied Linguistics is designed to be the essential one-volume resource for students. The book includes:
* qualitative, quantitative and mixed methods
* research techniques and approaches
* ethical considerations
* sample studies
* a glossary of key terms
* resources for students
As well as covering a range of methodological issues, it looks at numerous areas in depth, including language learning strategies, motivation, teacher beliefs, language and identity, pragmatics, vocabulary, and grammar. Comprehensive and accessible, this is the essential guide to research methods for undergraduate and postgraduate students in applied linguistics and language studies.