The concern for the students’ psychological health is an important aspect in order to obtain a qualitative learning system in the education environment. Misconceptions often pose strong barriers to understanding in science. As a consequence of traditional teaching, misconceptions can stick together with the learned scientific theories and are obvious in specific contexts, be it daily or academic. In this study, it is aimed to determined high school students’ ideas about concepts related to light before and after instruction. For this purpose, 30 students were asked 8 questions. Students’ ideas were grouped under "no answer", "misconception", "exactly answer" and "wrong answer" categories. After instruction most of the responses to these eight questions take part in scientific or scientific fragment categories.
