Analysis the quality of instrument for measuring chemical literacy abilities of high school student using Rasch model

Chemical Literacy Ability is an important aspect that students must have in chemistry learning. Assessment of students’ chemical literacy abilities is important to do to support more meaningful learning. This study aims to determine the instruments quality for measuring the chemical literacy abilities of high school students. The quality of the instrument measured includes three parameters, namely reliability, validity, and difficulty level of items. This research is a mix-method study with a sample of 80 high school students. Data were analyzed using the Rasch model with the Winsteps 3.73 software. The results show that the instruments made by researcher have high reliability (R = 0.96). The construct validity measured shows 41.90% of the raw variance, it means that the instrument has a good dimensionality. While the measurement of the difficulty level of the instrument was obtained by the item separation index of 5,11, which means that the instrument has a good distribution of items. Based on the above analysis results, the instruments made are feasible used to measure the chemical literacy abilities of high school students.