The purposes of this study were to adapt the Reformed Teaching Observation Protocol (RTOP) into
Turkish context, to examine the validity and the reliability of the scores obtained from this form and to address
preservice science and mathematics teachers (PSMT) constructivist-based instruction quality. A total number of
114 PSMT from a university in Turkey participated in this study. The construct validity of them was estimated by
exploratory and confirmatory factor analysis. The results of confirmatory factor analysis verified that the scale
with 25 items consists of four subscales as proposed. Each dimension derived from factor analysis had a
satisfactory reliability value. As a result, this study provided the Turkish adaptation of the RTOP observation form,
providing evidences for reliability, to the field. Moreover, it could be explained that PSMT could instruct their
lessons appropriate for constructivist-based teaching method effectively with respect to the results of this study.
Key words: Adaptation of observation protocol, reformed teaching observation protocol, constructivist-based teaching, preservice science and mathematics teachers.