This document discusses mixed methods research. It provides an overview of developments in mixed methods over the last 20 years, including increasing interest, evolving understanding of what constitutes mixed methods, and developing new designs and techniques. Mixed methods involves collecting and analyzing both quantitative and qualitative data within a single study to understand a research problem more completely. The document outlines reasons for taking a mixed methods approach, such as validity, offsetting weaknesses, completeness, explanation, and credibility. It also discusses preliminary design considerations and examples of concurrent and sequential mixed methods designs.