Accumulating evidence has shown the benefit of productive classroom dialogue for students’ learning achievement, higher-order thinking and conceptual understanding in school mathematics. However, eliciting high-quality classroom dialogue is challenging for teachers. Issues of teacher domination and limited, inequitable and passive student participation are frequently reported in Chinese mathematics classrooms. Recently, the potential of digital technology to foster classroom dialogue has been the focus of a growing body of research. One of the key claims is the need to support teachers and develop their pedagogical approaches. Thus, this study adopted a design-based research (DBR) approach to iteratively develop a teacher professional development (TPD) programme that integrated and adapted a lesson study model. Additionally, the study aimed to: (1) investigate changes in teachers’ understandings and practices of dialogic teaching with tablet technology; and (2) explore pedagogical strategies for supporting students’ active participation in dialogue while using online interactive platforms on tablets.

This one-year DBR study was conducted in two Chinese primary schools with seven mathematics teachers. The study included a pre-intervention assessment, two iterations of TPD based on parallel lesson study and a post-intervention assessment of teacher change. Data were mainly collected from individual teachers' baseline questionnaires, semi-structured teacher interviews and 27 lesson observations. Thematic analysis was employed to analyse the data collected from the interviews and open-ended questionnaire questions. The data concerning classroom dialogue were analysed at the lesson, episode and turn levels using a slightly adapted version of the T-SEDA coding scheme and an adaptation of the episode-level ‘Student Participation Rating Scale’.

The study found that the teachers developed multi-dimensional understandings of classroom dialogue and dialogic teaching, associated with specific features of technology-supported dialogue. Their emphasis on dialogic teaching shifted towards perspectives of students from that of teacher, foregrounding students’ active roles in participating in and contributing to dialogue and their learning outcomes. Students’ active participation in classroom dialogue and the quality of whole-class dialogue were significantly enhanced. The use of two online interactive platforms (Padlet, Zoomabc) created ‘blended dialogic space(s)’. A pedagogical framework for supporting students’ active participation in this 'blended dialogic space(s)’ was developed, encompassing components of classroom ethos, task design, participation structures, online dialogic interaction, face-to-face dialogue, and transitions and connections. The progressively developed teaching strategies in each component are reported and discussed.

This study fills a research gap regarding the use of the DBR approach for TPD design that incorporates the lesson study model to develop dialogic teaching with digital technology. The findings concerning technology-supported dialogic participation represent further progress in exploring the potential of interactions between digital technologies and classroom dialogue. The theoretical, methodological and practical contributions of the study, alongside their implications, are discussed.