Ability to notice and knowledge-based reasoning are, among others, components of teachers' professionalism important aspect needed for reflective practice and teacher's self-development. To foster these professional vision components, an online Observation Practice Course (OPC) was prepared.
Pre-service teachers (PSTs, N=11) underwent several lessons consisting of a critical incident's group video-observation, followed by group reflection and also their own written reflections with use of different reflective instruments. The main goal was to assess the course's effect on the PST's professional vision.
The initial and final reflections were later divided into information units (IUs) and analysed using several tools: Sherin and van Es' professional vision, Shulman's PCK and Slavík et al.'s 3A methodology. The PSTs' statements in the IUs were categorized into dimensions: actor, pedagogical-content and parsing strategy.
The difference between numbers of IUs between pre- and post-reflections was tested using Wilcoxon Single Rank Test with the r for the effect size. The results showed that the number of PSTs' IUs almost doubled as the result of the course.
Their attention significantly increased towards teacher (p = .003, r = .632) as well as teacher in interaction with students (p = .007, r = .570). In their reflections, the PSTs alteration dimension did not show statistically significant differences.
Their attention was also less focused on pedagogical dimension (p = .004, r = .632), shifted towards pedagogical-content dimension (p = .005, r = .598). The results thus show several successful OPC's aspects as well as some requiring further improvements.