This study aims to investigate the opinions of teachers working at public, private, and International Baccalaureate (IB) Schools on the evaluation practices, the use of assessment tools, the frequency of documenting data, and the feedback frequencies given to both students, and parents. A questionnaire has been used to collect data from 168 teachers. 84 of these teachers were from public schools, 30 from IB, and 54 from private schools. Percentages and frequencies were examined to describe the data, and the chi-square test was conducted for their distribution. There are two main conclusions derived. The first one is that state schools and private schools differ from IB schools in terms of exam-oriented preparation and evaluations when traditional methods are employed. The second one is that IB schools differ from state schools and private schools in terms of documenting the data and reporting of assessment for learning improvement and process-based evaluation. In terms of teachers' opinions, the ones from the IB schools believed there was a difference in terms of having an assessment policy, collaborative planning processes with partners, and experts, taking into consideration the individual differences, and having an inspection mechanism to monitor of the processes.