This report describes and provides research and scholarly support for a core practice of teaching--eliciting student thinking (EST)--that is the target for a performance assessment contributing one component of the "ETS"® National Observational Teaching Examination (NOTE) assessment series. The purpose of this report is to review the evidence supporting the importance of this practice for teaching, including how it has been conceptualized, studied, and represented in consensus literature on teaching. Then, the report describes the EST performance assessment together with the rationale for its design. The following are appended: (1) Sample EST Task; and (2) Sample Released Task for EST. [Some of the content in this report is used in the following companion reports: "Modeling and Explaining Content: Definition, Research Support, and Measurement of the 'ETS'® National Observational Teaching Examination (NOTE) Assessment Series. Research Memorandum No. RM-16-07" (ED570617); and "Leading a Classroom Discussion: Definition, Supportive Evidence, and Measurement of the 'ETS'® National Observational Teaching Examination (NOTE) Assessment Series. Research Memorandum No. RM-16-09" (ED570574).]