Penelitian ini bertujuan untuk mengembangkan instrument evaluasi two-tier multiple choice untuk mengukur literasi sains peserta didik menggunakan personal computer pada materi perubahan lingkungan yang layak dan menarik. Jenis penelitian ini yakni penelitian Research and Development (RD) yang menggunakan prosedur Borg and Gall sampai dengan 7 langkah. Dalam penelitian ini memakai data ahli media, ahli evaluasi, ahli bahasa, respon pendidik, respon peserta didik dan hasil literasi sains. Berdasarkan hasil penelitian bahwa instrument evaluasi two-tier multiple choice untuk mengukur literasi sains peserta didik X menggunakan personal computer pada materi perubahan lingkungan, dapat disimpulkan bahwa pengembangan instrumen evaluasi Two-tier multiple choice terhadap literasi sains berbantuan personal computer dengan metode pengembangan menurut Borg and Gall sampai langkah ketujuh diantaranya yakni Research and information collecting, planning, Develop prelimiery form of product, Prelimiery field testing, Main product revision, Main field testing dan Operational product revision. Setelah melakukan uji terhadap instrument evaluasi Two-tier multiple choice untuk mengukur literasi sains menggunakan personal computer pada mata pelajaran biologi telah diperoleh penilaian dengan kriteria sangat layak dan sangat menarik.

This paper aims to portray elementary teachers’ perception of implementing the Realistic Mathematics Education (RME) approach in their best practice after training in a series of RME workshops. The perceptions captured in the study include (1) teachers’ confidence in understanding RME and its implementation in their best practices; (2) RME criteria, which teachers found most challenging during the planning and the implementation. The subject of this study is 296 elementary teachers who have attended the training. The workshop series provided RME materials, simulation during the workshop, implementation in teachers’ best practices, and the workshop to discuss their experience. There are two findings in this study. Firstly, most teachers have a better understanding of RME characteristics. However, most teacher believe that the RME approach can be applied most mathematical topics. They felt confident in implementing the RME approach in their best practices. Secondly, teachers found that the most challenging when planned the RME lesson was finding suitable media related to mathematics topics. Moreover, during the implementation, teachers found it most challenging to lead students to formal mathematics. These results suggest that the most impactful workshop is better, followed by best practices and participants’ reflection afterward.