Adult education's mission is a critical one. It seeks to provide the large and diverse population of adults who lack basic skills, a high school credential, or English language skills with the competencies they need to be productive workers, family members, and citizens. Federally funded adult education serves learners in three types of programs: adult basic education, adult secondary education, and English as a second language. Nearly 43 million U.S. adults lack the basic English literacy skills required to succeed in the workforce and achieve economic self-sufficiency. The Workforce Innovation and Opportunity Act (WIOA) is the key federal investment helping adults acquire these and other important skills, as well as to earn a high school equivalency credential. WIOA encourages adult education programs to use evidence-based strategies to improve services and participant success. This systematic research review suggests a need for more rigorous studies, as there is not yet much evidence to guide decision making around instructional and support strategies for adult learners. Title II of the Workforce Innovation and Opportunity Act of 2014 directs the federal government to conduct a national assessment of adult education, including activities to understand the extent to which adult education strategies positively affect learners. A systematic review of the research on the effectiveness of particular strategies in adult education is one way in which the U.S. Department of Education is fulfilling this need. This snapshot reports on that systematic review. This is the first review of a broad set of strategies in adult education to apply the standards and procedures of the U.S. Department of Education's What Works Clearinghouse. It summarizes for policymakers and local providers the evidence base for many of the strategies authorized under Title II. It is designed to identify which strategies have evidence of effectiveness and where gaps appear in the evidence base. With this information, policymakers and practitioners can better understand the extent to which evidence supports particular strategies and which areas require additional studies. [For the appendices, see ED612199.]