The three-volume APA Handbook of Research Methods in Psychology includes descriptions of many techniques that psychologists and others have developed to help them pursue a shared understanding of why humans think, feel, and behave the way they do. Researchers use the Handbook for guidance choosing a method, researchers make decisions about what data or measurement techniques will best capture the thoughts, feelings, and behaviors that interest them; what research design best fits the question that they want to answer; and what strategies for data analysis best match the characteristics of their design and measurements. The earliest chapters in the handbook address the broadest questions related to research designs. Later handbook chapters describe the types of data that psychologists most often collect and how to determine whether the measurement techniques are the best ones for the research purpose. Issues and choices to be considered when writing up research to share with the community of psychologists are discussed in the handbook’s concluding chapters.