The document discusses education indicators and their functions. An indicator is defined as a measurable characteristic that shows progress toward achieving an outcome. Good indicators are specific, observable, unambiguously defined, and relate educational inputs to processes, outputs, and outcomes. Examples of indicators include student-teacher ratios and textbooks per student. The education production function underlies research on the effects of school resources, relating various inputs to outputs and outcomes. General features of a good indicator are that it is measurable, describes key features of the education system, links to goals, is relevant, problem-oriented, statistically valid, collectible, comprehensive, understandable, identifies trends over time, and applicable at different levels of the education system.