Authored by the absolute top authorities in quantitative and mixed methods research in this field. Introduces students to data analysis, and includes extensive coverage of research practices and related issues in design and methodology, and excellent coverage of a range of quantitative and mixed methods. Inclusion of the latter in a research text in applied linguistics is unique. Intuitive, chronological organization makes it easy for students to navigate and understand the book, while also being able to fruitfully consult individual chapters as needed. This organization allows students to conduct their own research studies from beginning to end. A wealth of graphics, visuals, exercises, practice tasks, boxes, and other pedagogic material provides students new to research with the necessary introductions to the key topics and debates in L2 research, as well as the tools to conduct their own research projects. There is no other core course text for SLA/L2-focused research design and analysis. Unlike other research methods core texts, Mackey/Gass focuses on L2 rather on applied linguistics more broadly. It therefore offers coverage of many more relevant methods. Also offers a hands-on guide so that students can conduct their own research. Mackey/Gass is much more user-friendly and well-written than extant books. Other books are a compilation of different contributions and styles without a unifying voice (or written as well as Mackey/Gass).