摘要：AbstractThis study was conducted to determine the views of high school students about proof and these students’ levels of proof. Case study method was used in this descriptive study. The data of the study were obtained by conducting a questionnaire which consists of eight open-ended questions to total 125 10thgrade students studying in two different secondary schools in Trabzon during 2006-2007 school year. The views of the students regarding proof were coded and their levels of proof were analyzed based on the classification of Miyazaki related to proof. At the end of the study, high school students’ competencies of doing proof were found below the desired level, as well as their use of different proof types. Based on these results, it's recommended to give room in the classes to activities that would improve students’ mathematical thinking skills and increase their levels of proof.
