The object of the present paper consists in the investigation of the scientific level of the specialized terminology used in school textbooks together with the determination of the characteristics of the terminological difficulties of the teaching matter.
The terminological exactness of textbooks as well as their comprehensibility have been investigated by means of quantitative characteristics based on qualitative and quantitative structural features of terminological elements incorporated in the subject-matter. For the purpose of this investigation of the terminological exactness and comprehensibility of textbooks an assembly of characteristics has been developed, applicable even to texts of high extent. These are submitted to test in comparative analysis of a sample of textbooks in a model teaching object where fundamental modernization has been realized. From the results of this analysis conclusions on the possibilities of reductions of the terminological „burdensomeness“ (in maintaining maximal exactness possible) as well as on the determination of the basic subject-matter are deduced.