The purpose of the article is to recognize the semantic frame that was built around the concept of quality in Chilean school policies between 1979 and 1984 and to develop a conceptual historical analysis from three types of sources: legal documents; documents from government institutions and documents related to the public discussion around this topic. Using the conceptual history approach, we recognized three layers of significance of the concept: quality linked to the reorganization of the school system; quality conceived as an effect of the school on the learning of the students, and quality as a result of performance measurements with their interpretations and possible use of these results. Around this last stratum, a dispute arose between political decision-makers and technical experts in measuring instruments, understood exclusively in terms of school performance, and leaving aside a broader sense of quality that goes beyond measured performance. Finally, after the historical reconstruction, we identify the logic underlying these layers of significance and we mention some implications of the historical findings for the study of the role that the concept of quality plays in contemporary educational policies.