The Influence of Open-Ended Approach with Group-To-Group Strategy on the Improvement of Mathematic Communication Skills for High School Students

. An open-ended approach with a group-to-group strategy has been used to support increased understanding, reasoning, and mathematical problem-solving abilities. However, experimentation on the effectiveness of this approach has not been explored much in supporting the improvement of students' mathematical communication skills. This experimental study aims to compare the mathematical communication skills of students who receive the open-ended group-to-group strategy treatment to students who receive conventional learning. This study involved 75 students in Wae Nakeng Santa Familia Senior High School, West Manggarai Regency, Indonesia. The data were collected by means of tests, and the t test was applied to compare the abilities of the two groups. Based on the results of the analysis, it can be concluded that the mathematical communication skills of students who accept open-ended with the group-to-group plan method are better than students in conventional classes.