Physics learning plays a very important role in everyday life, therefore, students' understanding of physics material is very important. Students who understand physics concepts well will find it easier to apply these physics concepts in everyday life. However, some students had difficulty understanding physics material, especially when they misunderstood the concept. Physics concepts formed webs that were connected to one another, so that a correct understanding at the previous level was one of the determining factors for success. The purpose of this research was to develop an e-Diagnostic based on the Certainty of Response Index (CRI) with the help of Google Forms to identify students' misconceptions about simple harmonic motion material. The type of research used was Research and Development which was adapted from the Four-D model. Grade 10 students were used as research subjects. The data described were in the form of instrument validity and results of identifying misconception profiles in students. The results of the validity test conducted by 2 experts and 8 colleagues stated that the developed test instrument was feasible to use. The results of the identification of misconceptions that were carried out showed that there were misconceptions, especially in the restoration style sub-topic. In conclusion, the e-Diagnostics that was developed is feasible to use as a tool to identify student misconceptions.

This research develops an interactive physics e-book to provide innovation in physics learning at schools. The purpose of the study was to determine the feasibility of a physics e-book on simple harmonic motion material, to determine the reduction of student misunderstandings after learning using e-books, and to determine the practicality of the e-books developed. This research uses research and development (R&D) methods with the research subjects of class X students. Based on learning innovations that have been carried out, it was concluded that e-book learning media has been developed to reduce student misunderstandings. E-book has been validated by 3 experts and the result are very good so it is suitable for use in learning. There is a reduction in student misunderstandings in modeling and implementation classes. The largest decrease occurred in the implementation class which was 11.00% while the modeling class was 9.00%. The e-books used successfully improved students' understanding by 18.00% in classroom modeling and 48.00% in implementation classes. The effectiveness of e-books in reducing student misconceptions belongs to the medium criteria in all classes. The practicality of e-books in modeling and implementation classes belongs to very good criteria.