The goal of this research is to make an epistemological analysis of methods used by high school teachers in teaching process and their measurement and evaluation preferences. The research is based on descriptive model and conducted on a total of 819 teachers. Data are collected through information form and analyzed with scientific statistical techniques. At the end of the analyses, it is observed that high school teachers participated in the research are partially sufficient in terms of epistemological belief; but these teachers stated that they highly benefit from the nature of knowledge while teaching a topic and conducting an exam. As there seems to be a dilemma between the statements and practices of teachers, the statements are found questionable. Participant teachers preferred the method of presentation in teaching process while they preferred conducting written exams in measurement-evaluation processes. These preferences justified the questionable point. This situation, which reveals the epistemological deficiency of teachers who participated in the research, is also an indication of epistemological discrepancy between current education programs and teachers. This indication shows that modern constructivist education programs in Turkey are practiced in a traditional sense. Putting education programs into practice by epistemologically destroying their nature is a serious risk that can prevent Turkey from reaching educational goals. It is known that constructivist approach makes significant contributions to ensure efficient education and to the process of raising creative individuals.