An application of many-facet Rasch measurement to validate the numeracy test for elementary students

Numeracy skills are essential for students' academic achievement and everyday decision-making; however, appropriate evaluation instruments are lacking. The main objective of this study was to investigate the psychometric characteristics of a numeracy test consisting of 16 items (12 multiple-choice and four essays), which were evaluated by 12 expert raters. This study utilized the Many-Facet Rasch Measurement (MFRM) to examine item difficulty, rater severity, and participant ability, thus providing an in-depth assessment of the validity and reliability of the test. The findings showed that all 16 items fit the Rasch model, exhibiting appropriate difficulty levels and ensuring that the test effectively differentiated participants' diverse levels of numeracy ability. In addition, the study demonstrated a uniform rater performance, thereby increasing the dependability of the evaluation. This study highlights the need for modern psychometric techniques in educational evaluation to create more effective instruments for assessing numeracy in mathematics education. This study promotes mathematical assessment and offers a basis for future research to improve educational measurement techniques.