Evaluation of the adequacy of history textbooks taught in secondary education in terms of content according to teachers

This study deals with teachers' evaluation of the content validity of history textbooks taught in secondary education institutions in Turkey. The main purpose of the study is to measure the content validity of history textbooks and test the hypotheses. The study followed a comprehensive methodology to test the hypotheses and measure the content validity of history textbooks. In this context, the research, which was conducted with the participation of 340 teachers, followed a two-stage data collection process. In the first stage, teachers' demographic and professional information was collected using the Descriptive Information Form, while the second stage involved the evaluation of the content validity of the textbooks using the Questionnaire on Content Validity of Textbooks. The collected data were analyzed using IBM SPSS 28 and evaluated with statistical methods. The findings of the study revealed that especially experienced teachers evaluated the textbooks in different dimensions and that the content adequacy of the textbooks varied according to their length of service. These findings emphasize the need for continuous improvement and updating of the content of history textbooks and show that teachers' experience plays an important role in this process. This study provides important findings on the content adequacy of history textbooks and emphasizes that teachers' length of service is determinant on their evaluations