The aim of study is to determine the effect of Prediction-Observation-Explanation (POE) and inquiry based learning methods which were applied in General Physics Laboratory 1 for science Teaching 1st class pre-service teachers. The sample is composed of 55 people, 27 of them in Group 1, 28 people in Group 2, all of whom are Science Education department students receiving the course of General Physics Laboratory. The model of this study is experimental pattern without pre and post-test control group. Group 1 was applied POE method, group 2 was applied Inquiry-based Learning method. Data of the study was collected with California Critical Thinking Tendency Scale and Scientific Process Skills Test. As a result of the study, while there was no statistically significant difference in scientific process skills of pre-service teachers who are applied with POE method in laboratory courses, there was statistically significant development in curiosity sub-dimension of critical thinking tendencies. In laboratory courses applied with Inquiry-based Learning method, there was statistically significant difference in scientific process skills and curiosity sub-dimension of critical thinking tendencies.
