We consider the use of text processing and analysis methods to create an automatic knowledge control system that evaluates the learning and understanding of educational material based on written answers. We indicate the part of the knowledge control system where semantic analysis of texts takes place. the system uses a text similarity algorithm based on distributive relationships, as well as a specific method for calculating the score of foreign words or formulas. The text processing methods used are described; the place of semantic analysis in knowledge control systems is shown, an example of the algorithm's operation on real data is given. The results of this article show that using this system has a significant impact on the educational process and is a viable solution. © 2020 IEEE.