The third edition of the bestselling text Research Design enables readers to compare three approaches to research - qualitative, quantitative and mixed methods - in a single research methods text. The book presents these three approaches side by side within the context of the process of research from the beginning steps of philosophical assumptions to the writing and presenting of research. The third edition presents the preliminary steps of using philosophical assumptions in the beginning of the book. It provides an expanded discussion on ethical issues. It emphasizes new Web-based technologies for literature searches. It offers updated information about mixed-methods research procedures. It contains a glossary of terms.