The Impact of Online Video-Based Teacher Professional Development on Instructional Practices and Student Achievement in Biology

This study aimed to examine the effects of online, video-based teacher professional development on changes in classroom instruction and student achievement in biology. The professional development program included organizing lessons based on prepared materials aligned with national curriculum outcomes, asynchronous participation in an online forum for (self-)analysis of lesson videos using the Teaching Observation Form (TOF), and synchronous participation in online communities of practice. Teachers and their eighth-grade students participated in this quasi-experimental study, which involved control and experimental student groups and pre- and post-tests of knowledge. The results indicate that students in the experimental group achieved statistically significantly higher post-test scores than those in the control group (d = 0.26), with the largest differences observed in tasks requiring higher-order cognitive skills. The findings suggest that even a relatively short professional development intervention—including continuous online support for teachers—can lead to improvements in student learning outcomes.