This is the second in a series of policy notes and related publications exploring prospects for developing indicators of teaching quality. The first examined federal databases that include information about teachers, demonstrating that almost none of the measures in these datasets provides indication of teaching quality. This policy note takes the next step by concentrating on measures of instruction associated with valued outcomes for students, using a tripartite set of indicators--structural, process, and outcome--to guide policy and decision making. After an overview about indicators in general, this report looks at indicators specifically as they apply to the K-12 education sector, discussing how there is no shortage of structural (inputs) and outcome (assessments of learning) indicators before delving into the gap in process indicators (measures of quality of instruction). One example is explored of how such indicators of instruction have been developed and used in early childhood education (ECE) in regard to the federal Head Start program. [For the first report, "Quest for Quality: An Indicator System for Teaching. Equity in Education Series. Policy Notes," see ED595421.]