Designing and enacting mathematics lessons: Insights from pre-service teachers’ learning through project-based learning and lesson study
Bridging lesson design and instructional enactment remains a challenge in mathematics teacher education. This qualitative case study explored how Project-Based Learning (PjBL) and lesson study supported pre-service mathematics teachers (PSTs) in addressing this challenge. PjBL provided the macro-pedagogical architecture for a seven-week collaborative project, while LS structured the micro-cycles of Plan, Do, See, and Redesign. Participants were 13 third-year PSTs enrolled in an undergraduate Mathematics Education program and taking an Elementary Mathematics Instruction course at an Indonesian university. Organized into three groups, they selected an elementary mathematics topic, designed a two-meeting lesson sequence, and completed two lesson study cycles through peer teaching. Data consisted of lesson designs and semi-structured group interviews and were analyzed thematically. The findings revealed that participants engaged in pedagogical reasoning, designed tasks intended to promote mathematical reasoning and communication, considered simulated learner responses, and used reflection to redesign their lessons. However, interview data revealed instances of reverting to direct explanation when simulated learners hesitated or required additional time. These findings identify a design–enactment discontinuity in which the capacity to construct student-centered lessons did not automatically translate into responsive enactment. The study suggests that combining sustained project work with iterative professional inquiry can provide a useful structure for lesson design, but PSTs also require repeated and scaffolded opportunities to rehearse responding to learner thinking.