This paper explores how Bulgarian teachers and school principals interpret the meaning of digitalisation in education, drawing data from a mixed-method study. The study is part of the national research project SUMMIT and builds upon a representative quantitative survey conducted in 359 schools across Bulgaria, on the one hand, and a qualitative study with a focus on a stratified sample of 30 schools, on the other hand. Data was collected through in-depth interviews with 221 teachers and 30 principals.

Thematic analysis reveals that teachers’ conceptualisations of digitalisation vary significantly depending on the subject they teach. Teachers of Mathematics, ICT, and Foreign Languages tend to associate digitalisation with specific tools, platforms, and enhanced efficiency. In contrast, educators in Social Sciences and Primary Education highlight pedagogical transformation, student motivation, and the creation of new learning environments. A shared understanding across subjects is the connection between digitalisation and increased learner engagement.

Differences in interpretation of the digitalisation also emerge across teaching experience and educational context. Teachers with less than five years of experience often refer to digitalisation as a set of tools, while more experienced educators reflect on how digitalisation transforms roles, methods, and content. Participants from rural areas and small schools frequently describe digitalisation as a challenge, citing infrastructural limitations and digital divides. In contrast, teachers in regional cities or larger schools are more likely to highlight opportunities for innovation and collaboration.

Principals’ responses echo some of these themes but add an institutional perspective. Many describe digitalisation as an ongoing organisational process involving school leadership, staff development, and strategic planning. There is evidence that principals from larger or urban schools perceive digitalisation more holistically, incorporating infrastructure, staff readiness, and pedagogical vision. Those from smaller or rural schools tend to focus on obstacles such as insufficient equipment and limited local support.

The qualitative coding resulted in four dominant interpretive categories: digitalisation as infrastructure and equipment, as pedagogical innovation, as a challenge or barrier, and as a strategic and institutional process. These categories are not mutually exclusive but are shaped by the respondents’ roles, teaching subjects, experience, and school contexts.

Overall, the study finds that digitalisation is understood in multifaceted ways. These diverse interpretations underline the importance of differentiated policy approaches and targeted professional development. The findings also suggest that fostering a shared vision of digital transformation in schools requires active dialogue and support at both pedagogical and institutional levels.

Keywords: Digitalisation in education, teacher perceptions, school leadership, pedagogical innovation.