
By exploring the Science Teacher program students’ misconceptions, this study is aimed to eliminate their misconceptions about geometric optics with conceptual change texts. At the first stage, the data were obtained by applying a three-tiered multiple choice test containing 19 questions, improved for Agri Education Faculty Science Teaching Department 90 sophomore students and a classic exam related to the subject in autumn season. To determine misconceptions concerning the geometric optics, randomly chosen 10 sophomore students were interviewed with 10 open-ended questions. Findings obtained from the test and interviews showed that students have misconceptions about “propagation of light”, “reflection of light” and “refraction of light”. At the second stage, the sample composed of 90 students was separated into two group as experimental group and control group. The conceptual change texts were prepared then to apply for instructional method in experimental group. By being parallel to each other conceptual change text method for experimental group and traditional lecturing method for control group were applied respectively. Later the test consisting 19 multiple choice test were applied as post-test in both experimental and control group. The data appearing coherent of 35 each of experimental and control group were taken into consideration. Reliability of the test that used as pre-test and post-tests were calculated by Cronbach-Alfa coefficient as 0,69 by using SPSS-11 for Windows. The study showed that the conceptual change texts are more effective than traditional method for instruction to eliminate students’ misconceptions about geometric optics.