The effect of blended learning environment on pre-service science teachers' technological pedagogical content knowledge and classroom teaching practices in the topic of global warming

The aim of this longitudinal-experimental research is to develop Pre-service Science Teachers' (PSTs) Technological Pedagogical Content Knowledge (TPACK) and classroom teaching practices, involving the topic of global warming (GW). In this study, it was aimed to develop PSTs' Technological Pedagogical Content Knowledge (TPACK) and classroom practices as part of Science Methods Course-II (SMC-II), School Experience (SE) and Teaching Practice (TP) desgined and performed based on blended learning environment. In accordance with the aim of the study, 69 PSTs in their final year participated in this study. The PSTs were randomly assigned as experimental (N=35) and control group (N=34). While SMC-II, SE and TP were taught through only face to face learning environment for the control group, these courses were carried out through blended learning environment developed by considering the power sides of face to face and online learning for the experimental group. Blended learning designed for the experimental group was constituted as a result of being effectively blended with face to face learning and four main online systems (Moodle Learning Management System, Web-Authentic Assessment System, Collaborative Argumentative Repository of Learning Objects and Mahara Electronic Portfolio) and 18 subcomponents of these online systems. In this qualitative and quantitative study, the data were collected based on triangulation approach. The vignette based semi-structured individual interview and Content-Representation for the PSTs' TPACK and its components; field notes, video records and Reformed Teaching Observation Protocol (RTOP) for the PSTs' classroom teaching practices were used as data collection tools in this study. The data for the PSTs' TPACK and classroom teaching practices were collected in the beginning, middle and final of the academic year. The results of statistical analyses (Doubly Manova) for PSTs' TPACK and its components and classroom teaching practices showed that while there were no statistically significant differences between both groups in terms of comparison of pre- and mid-test results (p>0.05), but the experimental groups were statistically better than the control groups from mid- to post-test results (except for TCK) for all dependent variables (p<0.01). The results have been discussed in terms of Turkish teacher education programs. Keywords: Blended Learning, Classroom Teaching, Global Warming, PCK, Teacher Education, TPACK