The use of national assessment data has increasingly been positioned as a foundation for instructional decision-making in schools. In Indonesia, Rapor Pendidikan (Education Report Card) was developed as a national platform providing school-level quality data, including students’ literacy and numeracy achievement. However, the availability of data does not necessarily correspond to changes in classroom practice. This study aims to analyze how principals and teachers interpret and use literacy and numeracy data presented in Rapor Pendidikan by positioning it as a boundary object. This research employed a qualitative case study design. Data were collected through semi-structured interviews with the principal and teachers, document analysis of Rapor Pendidikan, and reflective field notes. Findings indicate that Rapor Pendidikan is jointly recognized and accessed by various school actors; however, it primarily functions as an informational artifact rather than as a basis for instructional decision-making. No systematic mediation practices were identified that connect data indicators with classroom instructional decisions. These findings suggest a stalled boundary crossing condition, in which data are recognized and understood but not translated into pedagogical action. The study underscores that educational data use constitutes a social practice dependent on instructional leadership, professional collaboration, and collective sensemaking at the school level.
