Abstract
This study examines the improvement of mathematical communication skills in elementary school students by applying geometry learning based on van Hiele's theory and routine learning. A quasi-experimental quantitative survey method using a non-equivalent control group design. Participants totaled 63 people, not taken randomly. The instrument used is a test in the form of an essay; the questions are set in the form of mathematical communication skills. Data analysis used descriptive statistical tests and inferential statistics using the Mann-Whitney test. Research findings namely; Learning geometry based on Van Hiele's theory has an influence on mathematical communication skills in mathematics learning for elementary school students with a very high category; Improvement in mathematical communication skills between students learning geometry learning based on Van Hiele's theory and those learning applying conventional learning was a low category of performance; The improvement in mathematical communication skills among students learning geometry based on Van Hiele's theory is better than students learning through traditional learning.