Developing Diagnostic Test on Geometrical Optics (DT-GO) Topics Jajang Kunaedi, Achmad Samsudin, Lilik Hasanah, Adam Aminudin, Fanny Herliyana Dewi, Fini Alfionita Umar, Itsna Rona Wahyu Astuti, Shobrina Nurul Mufida
Universitas Pendidikan Indonesia
Abstract
The purpose of this research is to develop the instrument of diagnostic test on optical geometry material, especially in the mirror and lens topics, as well as to unveil the misconceptions of students at one of the public schools in Subang Regency. Determination of the population in this study was carried out by purposive technique sampling with sample selection utilising cluster random sampling technique with a total of 96 respondents. The instrument utilised by modifying the Four Tier Diagnostic Test which is developed by Kaltakci-Gurel (2017) is Developing Diagnostic Test on Geometrical Optics (DT-GO). The results of the instrument analysis on the validity test, reliability test, difficulty level test and discriminatory power state that the instrument was very well utilised and developed. Based on data analysis and discussion, it can be concluded that overall misconceptions had occurred of overall misconceptions that occur in students are 42.04 %, thus they meet the requirements for misconceptions to a moderate level.
