Pelaksanaan penilaian autentik dilakukan guru tanpa menggunakan instrumen penilaian sebagaimana mestinya. Penelitian ini bertujuan untuk menggambarkan pelaksanaan penilaian autentik kurikulum 2013 dalam pembelajaran tematik kelas 1. Penelitian ini menggunakan metode kualitatif dengan jenis field research secara deskriptif. Informan dalam penelitian yaitu guru kelas satu, siswa kelas 1A dan wakil bidang kesiswaan. Instrumen pengumpulan data dilakukan melalui observasi, wawancara, dan dokumentasi. Teknik analisis data dilakukan dengan menggunakan model Miles dan Huberman, lalu diuji keabsahan data menggunakan triangulasi sumber. Hasi penelitian menggambarkan bahwa pelaksanaan penilaian autentik kurikulum 2013 di kelas 1 belum secara optimal diterapkan oleh guru. Hal tersebut dikarenakan guru kerap kurang menyiapkan instrumen terkait dengan penilaian afektif dan psikomotornya. Pada penilaian bagian afektif guru hanya menilai siswa dari kesehariannya saja. Sedangkan pada bagian penilaian psikomotor guru hanya menilai dari hasil keterampilan siswa tanpa membuat rubik penilaian.

The research carried out aims to determine the inhibiting factors of teachers in thematic learning in elementary school. This type of research uses a qualitative approach with descriptive methods. The data collection technique used is a literature study. The result of the research analysis shows that at the planning stage teachers have difficulty in preparing syllabi and lesson plans according to the conditions and environment of students, teachers also find it difficult to prepare appropriate learning media in thematic learning. Meanwhile, at the implementation stage, the teacher had difficulty in adjusting the time allocation with learning and the demands of completing one learning in one meeting, this had an impact on the basic competency adjustment with learning material in half a day, it was difficult to synergize the delivery of objectives and apply a scientific approach to learning. So as to better understand the concepts and implementation of thematic learning.