The characteristics of chemistry test items on nationally-standardized school examination in Yogyakarta City

This study aimed to describe the characteristics of chemistry test items in Nationally Standardized School Examination or Ujian Sekolah Berstandar Nasional (USBN), consisted of discrimination index, difficulty index, and question reliability. The data was collected by using documentation of the answers of 194 students. The type of research was descriptive exploratory with quantitative and qualitative approaches. Quantitative data analysis was performed by using classical test theory approach and item response theory with 1 logistical parameter. Meanwhile, qualitative data analysis was conducted in order to describe the items that were categorized as difficult and bad categories. The results showed that according to classical test theory, USBN Chemistry item test had an average level of difficulty of 0.57 which was categorized as moderate. Regarding to the discrimination index, the average of different test power obtained were equal to 0.146, and belonged to the good category. Based on the item response theory, the average of difficulty index of -0,00086 was categorized as moderate. The results of the estimated reliability of the questions amounted to 0.48 included in the moderate category. The results of the qualitative analysis showed that the items which belonged to difficult category were the items on salt hydrolysis material, acid-base titration, the concept of periodicity, manufacture and use of chemical compounds according to classical test theory. Meanwhile, according to the theory of response, items which belonged to difficult category were found in acid-base titration material, the solution colligative phenomenon, and the concept of periodicity of the main metal elements.