International Journal for Multidisciplinary Research (IJFMR) E-ISSN: 2582-2160 ● Website: www.ijfmr.com ● Email: editor@ijfmr.com IJFMR22061068 Volume 4, Issue 6, November-December 2022 1 Collaborative Learning's Effect on Mathematical Communication Skill Ade Nandang Mustafa Mathematics Education Department, Universitas Sultan Ageng Tirtayasa, Indonesia Abstract- This study aims to determine the increase in mathematical communication skills through Collaborative Learning. This study is an experimental study with a pre-test post-test control group design. Researchers randomly selected two groups of 30 students each from 183 Grade 8 students at a junior high school in Lembang, Indonesia. The mathematical communication skills test is used as a measuring instrument. Quantitative data analysis was performed using t-test, Mann-Whitney, and Rank- Spearman. The results showed that the increase in the mathematical communication skills of students who received Collaborative Learning was better than students who received conventional learning. Keywords- Collaborative Learning, Mathematical Communication Skill INTRODUCTION Collaborative learning (CL) is a pedagogical technique in which students learn cooperatively in a group environment with the assistance of others(Oxford, 1997). Collaborative learning (CL) is a frequently used pedagogical technique in recent years, particularly in STEM areas such as mathematics and physics(Jeong et al., 2019). Students employ their knowledge and abilities in teams to tackle open-ended issues(Nurhayati, 2016;Hobri et al., 2019). This methodology encourages active learning and strengthens peer relationships(Shokri & Dafoulas, 2015). The three main components of CL are student collaboration, cooperative learning, and scaffolding(Hornby & Greaves, 2022). CL helps students to be more successful by fostering these three key components. Those three components work together to help students achieve academic success. Student collaboration: The first component of CL is collaborative learning, which consists of group activities in which students work together to solve a problem or accomplish a task. Students are encouraged to discuss and share their ideas in a collaborative learning atmosphere. This atmosphere is accomplished with the assistance of a leader and a facilitator. The leader conducts the discussion by providing the class with direction, while the facilitator keeps track of time and ensures that everyone has an opportunity to speak. This system allows all students to participate in the discussion and better understand the topic. Cooperative learning: The second component of collaborative learning is collaborative learning, which is closely related to student collaboration. In a cooperative learning environment, students do assignments as a team. In addition, they are broken into smaller groups for practical exercises. Then, these groups convene to exchange their experiences and consolidate their knowledge. In addition, they encourage one another by contributing fresh ideas and providing other resources that may be useful to their project. Students enhance their communication skills and learn how to operate effectively as a team