A Comprehensive Evaluation of Mathematical Communication: Validity and Reliability Evidence in Assessment Instruments

Abstract

This study aims to provide a comprehensive evaluation of a mathematical communication assessment instrument by examining its validity and reliability through both expert judgment and empirical testing. High-quality instruments are essential to ensure that the data collected accurately represent students’ abilities and align with the intended constructs of mathematical communication. The validation process in this study involved mathematics education experts who reviewed the content relevance, clarity, and alignment of each item with the established indicators. In addition, a small-scale trial was conducted with students to obtain empirical evidence of item performance. The trial results indicated strong item–total correlations that exceeded the critical values in the validity table, demonstrating that each item adequately measured the intended aspects of mathematical communication. Reliability analysis was carried out using the test–retest method supported by Cronbach’s Alpha to assess the internal consistency and stability of the instrument. The obtained coefficient of 0.812 reflects a high level of reliability, indicating that the instrument consistently yields dependable results across multiple administrations. These findings collectively confirm that the instrument possesses both strong validity and high reliability, providing solid evidence of its technical quality. Overall, this assessment instrument can be confidently used to evaluate students’ mathematical communication skills in various instructional contexts. The validated instrument offers a robust foundation for further analysis in mathematics learning, supports the evaluation of communication-focused pedagogical strategies, and contributes to the development of evidence-based practices aimed at improving students’ mathematical understanding and expression.