Single-case research design (SCRD) is a practical methodology that allows school counselors to explore the impact and outcomes of interventions specifically for the purpose of determining their effectiveness with individuals and single cohort groups. This chapter provides identification and definitions of terms specific to SCRD. It also provides descriptions of essential characteristics of SCRD, including continuous assessment, baseline data collection, and phase stability. It presents step-by-step instructions on how to conduct an SCRD and uses case examples to demonstrate each step of the process. The chapter further provides tables, figures, and graphs to illustrate the implementation of SCRD visual analysis.