The Effect of the Inquiry-Based Learning Model on Students’ Mathematical Communication Skills: A Quasi-Experimental Study

Abstract

Mathematical communication skills are essential in mathematics learning because they enable students to express mathematical ideas, use representations, explain solution processes, and construct logical arguments. This study aimed to examine the effect of the Inquiry-Based Learning (IBL) model on students’ mathematical communication skills. A quantitative approach with a quasi-experimental pretest–posttest control group design was employed. The participants were 68 Grade XI students of SMA Negeri 1 Sedayu, consisting of an experimental group that received Inquiry-Based Learning and a control group that received conventional instruction. Data were collected using a five-item open-ended mathematical communication test developed based on mathematical communication indicators. The instrument demonstrated acceptable validity and reliability, with Cronbach’s alpha coefficients of 0.870 for the pretest and 0.704 for the posttest. Data were analyzed using descriptive statistics, prerequisite tests, analysis of covariance (ANCOVA), N-Gain analysis, and Cohen’s d effect size. The ANCOVA results showed that, after controlling for students’ initial abilities, the instructional group had a significant effect on posttest mathematical communication scores (F(1,65)=25.477, p<0.001, partial η²=0.282). The experimental group also obtained a higher average N-Gain score (44.14%, moderate category) compared with the control group (25.39%, low category), with a large effect size (d=1.23). These findings indicate that Inquiry-Based Learning provides a meaningful learning approach for supporting students’ mathematical communication skills by encouraging them to express ideas, use mathematical representations, explain reasoning, and construct arguments.