The Quality of Instrument Used to Measure Mathematical Reasoning Ability of Junior High School Students

Abstract

The quality of an instrument considerably determines the quality of the obtained data. The accuracy of a research finding is determined by the quality of its data. Therefore, the quality of one instrument determines the results of research. The quality of instrument used in measuring mathematical reasoning ability was analyzed by including 6 indicators of mathematical reasoning ability and involving 332 students of the Junior high school in Samarinda. They were selected by using Proportional Cluster Random Sampling method. The quality of instrument items was analyzed by using SPSS program and LISREL 8.8. The research findings showed that the instrument for mathematical reasoning ability had met the requirements of content validity, construct validity, moderate reliability coefficient, statistically significant discriminating power and moderate difficulty index. Therefore, this instrument had met the requirement of the instrument with a good quality.