In evaluation and applied social research, focus groups may be used to gather different kinds of evidence (e.g., opinion, tacit knowledge). In this article, we argue that making focus group design choices explicitly in relation to the type of evidence required would enhance the empirical value and rigor associated with focus group utilization. We offer a descriptive framework to highlight contrasting design characteristics and the type of evidence they generate. We present examples of focus groups from education and healthcare evaluations to illustrate the relationship between focus group evidence, design, and how focus groups are conducted. To enhance the credibility of focus group evidence and maximize potential learning from this popular qualitative data collection method, we offer a set of questions to guide evaluators reflection and decision making about focus group design and implementation.