In the first part, the paper considers the important role of teacher’s requirements in relation to knowledge assessment. In the second part, the results of empirical research carried out in March 2006 in Slovenian grammar schools are presented. Knowledge assessment is an independent stage of the learning process performing its own specific didactic function (Strmčnik 2001). Knowledge assessment is significantly integrated into a class lesson. Together with lesson plans codetermines what should be instructed and taught, and thus determines the quality of a lesson. (Bucik 2001). It is important thus to see what are the most important things that teachers take into consideration when assessing knowledge: the exact recap of the content of data (names, dates, figures etc.), exact repetition of definitions, subject comprehension, applying of what has been studied in the classroom into novel situations, pupils’ critical approach to the subject, pupils’ own views and knowledge reflection, linking knowledge with other subjects, pupils’ quotes of new examples about the subject concerned (Ivanus Grmek et.al 2007).

With an empirical research was examend what are teacher’s content requirements in process of grading knowledge in Slovenian grammar schools. In the research 3104 students and 420 teachers in grammar schools were included. We were interested in the differences between the assessment of teachers and students regarding the content requirements of teachers when grading knowledge. The data was collected with anonymous questionnaires for teachers and students.

The results show differences in the judgement of the frequency of the teacher’s individual requirements among the group of teachers and students. The teachers estimate that when assessing knowledge they often demand: understanding, application, individual views and students' knowledge reflection. The students, however, think that they have to know: the exact repetition of definition, reproduction of notes from a course book or notebook and various data.