Diagnostic assessments play an important role in supporting an inclusive and differentiated approach to education, where education is tailored to students' varying ability levels and needs. Diagnostic assessment is an assessment process carried out with the aim of identifying individual student learning characteristics, competencies, strengths and weaknesses. The main aim of a diagnostic assessment is to understand more deeply the students' abilities, understanding, level of knowledge and needs in the learning context. Diagnostic assessments can involve a variety of assessment methods, including tests, observations, interviews, or observing student behavior. The results of the diagnostic assessment are used to assist educators and teachers in designing learning that suits students' needs and ability levels. Thus, diagnostic assessment is an important tool in curriculum development and effective education delivery.