From the perspective of the stages of learning, knowledge assessment is an independent stage of the learning process performing its own specific didactic function which does not coincide neither with examination nor with repetition, although it can be examination and repetition in some way. Knowledge assessment presents an integral part in a lesson and together with curricula determines what should be instructed and taught, and thus determines the quality of a lesson. The goals, which we defined by knowledge assessment, are of crucial importance here. According to Bloom's taxonomy for cognitive field we can assess knowledge, comprehension, application, analysis, synthesis and evaluation. 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 etc.Knowledge assessment, which stimulates the best results and is done inside a classroom, uses qualitative records, it is motivating and time consuming. It can be said that in this case the assessment is different, more genuine and authentic. It is thus the assessment which presents the integral part of a lesson and it is not stimulated from the needs of measurement only, as this is the case with various tests.In the research, which was carried out in the school year 2003/04, we were interested in the differences between the assessment of teachers and pupils with regard to the content requirements of teachers when assessing knowledge, and differences between the teachers of the Slovenian language and teachers of mathematics in the frequency of using authentic forms of knowledge assessment.In the research we used the descriptive and causal nonexperimental method of the pedagogical research. We included 345 pupils attending the seventh and eight grade of primary schools in the Republic of Slovenia and 98 teachers of the Slovenian language (46, 46.9%) and mathematics (52, 53.1%). We collected the pupils' data by using anonymous questionnaire during a lesson. The data among teachers was collected by sending questionnaires by post, and the anonymous questionnaire was used here as well. As far as the content requirements of teachers when assessing knowledge are concerned, the results showed differences in judgements of the frequency of individual requirements of teachers between the groups of teachers and pupils. Teachers say that their main requirements when assessing knowledge are comprehension, application, interdisciplinary connections and individual (also critical) views and pupils' reflection on a certain subject. By knowledge assessment, pupils say that they are required to know definitions, what is written in the notes and textbooks. They are also required to memorize data (years, names, figures). The other view we were interested in was the extension of the application of the authentic forms of knowledge assessment among teachers. We found that some individual authentic forms of knowledge assessment rarely appear, however, they are more widespread among teachers of the Slovenian language than among teachers of mathematics.