The challenge of expanding access to higher education without compromising quality is a central issue in educational policy worldwide. Brazil presents a paradigmatic case study of this dilemma, having undergone one of the world's largest expansions of higher education since the 1990s, a process largely driven by the leading role of the private sector and a massive shift towards distance learning (Distance Education). While this transformation has democratized access, it has also raised critical questions about the emergence of quality asymmetries. Despite the existence of a comprehensive national assessment system, there is a lack of long-term empirical evidence on the results of these policies.

This study aims to analyze the transformations in the quality of Brazilian higher education over three decades by investigating the association between structural changes and student performance outcomes. The research methodology is grounded in a longitudinal descriptive and comparative analysis of official datasets from Brazil's national student performance exams: the Exame Nacional de Cursos (ENC) and the Exame Nacional de Desempenho dos Estudantes (Enade). The analytical approach involves the calculation of descriptive statistics to map performance trends over three decades. Direct comparisons of student performance metrics are made across different categories of Higher Education Institutions (HEIs) and teaching modalities. The dimension of performance gaps is systematically quantified and tracked across different assessment cycles to identify patterns of convergence or divergence.

The findings reveal a persistent and, in many cases, widening performance gap between students from public, face-to-face HEIs and those from the distance education modality linked to for-profit private HEIs. The data indicates that while access has broadened, the system has concurrently produced deep-seated quality disparities, with different models of educational delivery leading to significantly different learning outcomes as measured by national standards.

This research, therefore, contributes with longitudinal empirical evidence that supports a critical reassessment of the Brazilian higher education expansion model. By quantifying the resulting asymmetries, this study offers subsidies for the enhancement of regulatory instruments and fosters a qualified debate on the necessary pathways to align expansion with the guarantee of consistent and equitable quality standards.

Keywords: Higher Education, Quality Assurance, Distance Education, Private Sector Expansion, Educational Policy.