This report presents the results of a 15-month evaluation design effort funded by the U.S. Department of Health and Human Services, Administration for Children and Families, Office of Planning, Research and Evaluation to develop options for a rigorous evaluation of the impact of Job Search Assistance (JSA) services on low-income workers. A partner report reviews current JSA programs and evidence on their effectiveness. The report presents a logic model as a foundation for specifying research questions for an evaluation. Though many important research questions exist, the report recommends focusing on the differential impact of JSA program variants on short-term earnings. Learning about the relative effectiveness of program components has the potential to inform program improvement and efficiencies, and the report argues that short-term earnings is the most policy relevant outcome.