The Impact of RADEC Learning Model on Mathematical Communication Ability: An Experimental Study on High School Students in Palu City

 The low mathematics learning outcomes of high school students in Palu City are caused by the weak mathematical communication skills of high school students. Therefore, a learning model is needed that can improve students' mathematical communication skills. The RADEC learning model was chosen to be implemented in mathematics learning in the classroom. This research method is a quasi-experimental method with an intact group comparison design. The population of the study was all grade X high school students in Palu City, totaling 3656 students, while the sample was 186 students in theexperimental class and 186 students in the control class. Sampling used a purposive random sampling technique. The instruments used were initial ability tests and mathematical communication ability tests. Data were analyzed using t-test statistics and two-way ANOVA test statistics. The results showed that the RADEC learning model had a higher impact on the mathematical communication skills of high school students in Palu City, with a significance level of p = 0.000. The average score of mathematical communication skills of students who follow the RADEC learning model is 76.70 on a scale of 0-100, while participants who follow Direct Instruction are 62.35. The RADEC learning model does not provide different impacts based on students' initial abilities, so this model can be implemented in classes with heterogeneity in students' initial abilities. Please find it detailly the link https://univtadulako-my.sharepoint.com/:b:/g/personal/astija_untad_ac_id/EUwpV9LdyPBKuPsIXapygf4BsOp4mziNBTPg_pAb06qNhw?e=pMtJlm