The Reliability of the Indonesian Pedagogy of Science Teaching Test (POSTT)

Abstract

The development of an instrument typically requires a reliability study. For formative assessment instruments, however, reliability is less of a concern unless a formative instrument gets used as a research tool or for summative purposes. When that happens, the formative instrument needs to be evaluated for reliability. The POSTT is one of those instruments that was developed for formative purposes and then subsequently used in research, but not much attention has been paid to reliability. Since only a few researchers have reported the reliability of the POSTT, it is important to investigate its reliability. This is a quantitative study with a secondary analysis of test/retest data. Seventeen preservice biology teachers in the fourth year of Biology department education were the respondents of the study. The data was collected using test/retest and analyzed using SPSS 26 software. The primary purpose of the study reported in this paper was to determine the reliability of the POSTT using a test and retest method. The results suggest test/retest coefficient do not support the Indo-POSTT as a reliable instrument. From eight items of Indo-POSTT, there is only one item that has significant high correlation coefficient. We conclude that the based on test/retest, the Indo-POSTT's reliability is not sufficient suggesting that this instrument is not stable. Therefore, a further investigation using other methods is needed.