Developing a valid hypothesis can be a sticking point in writing a research article, dissertation, or thesis. This concise, engaging guide shows readers how to write a precise hypothesis that reasonably explains the event being investigated and is testable through the collection and analysis of data. Key topics include defining the independent and dependent variables (“cause” and “effect”) needed to develop directional and non-directional hypotheses, the relationship between research and null hypotheses, the identification of data needed to test a hypothesis, and interpretation of the analyses. Examples are drawn from quantitative, qualitative, and mixed methods studies from a variety of disciplines; case study exercises offer learn-by-doing practice opportunities. Other pedagogical features include chapter objectives, boxed key words and concepts, tips on things to do and avoid, and an end-of-book glossary.