Penelitian ini mendeskripsikan tentang evaluasi pelaksanaan penilaian autenti kurikulum 2013 dalam pembelajaran biologi kelas X IPA di SMA Tarakan. Penelitian ini bertujuan untuk mengetahui pelaksanaan penilaian autentik yang dilakukan oleh guru di SMA Negeri 3 dan SMA Tunas Kasih Tarakan. Penelitian ini menggunakan penelitian deskriptif kualitatif. Subjek pada penelitian ini adalah 2 orang guru biologi di SMA Negeri 3 dan SMA Tunas Kasih Tarakan, dan peserta didik kelas X IPA dikedua SMA tersebut. Pengumpulan data dilakukan dengan menggunakan angket yang dibagikan kepada guru biologi di masing-masing sekolah , kemudian dilakukan wawancara dan dokumentasi. Hasil penelitian menunjukan pada sekolah SMA Negeri 3 Tarakan dengan capaian pada aspek perencanaan 100%, pelaksanaan 100%, pelaporan 100%, penilaian sikap 100%, pengetahuan 100% dan keterampilan 100% , sedangkan pada sekolah SMA Tunas Kasih Tarakan pada aspek perencanaan 100%, pelaksanaan 100%, pelaporan 100%, sikap 40%, pengetahuan 100%, dan keterampilan 71%, guru sudah melakukan penilaian autentik pada saat proses pembelajaran yang meliputi komptensi sikap, pengetahuan, dan keterampilan. Namun, dalam pelaksanaan penilaian autentik belum sepenuhnya dilaksanakan secara optimal pada aspek sikap dan keterampilan. Faktor penghambat pelaksanaan penilaian autentik yaitu (1) ketersedian waktu, (2) ketersedian LKS , (3) ketersedian fasilitas seperti Lcd, dan akses internet. Faktor pendukung pelaksanaan penilaian autentik yaitu (1) peserta didik, (2) ruang kelas.

This study described the evaluation of authentic assessment implementation of 2013 curriculum in biology instruction for class X IPA at Senior High School in Tarakan. The objective this study was to find out the implementation of authentic assessment conducted by the teachers at SMA Negeri 3 Tarakan and SMA Tunas Kasih Tarakan. This study employed a descriptive qualitative reseach. The subjects of this were two biology teachers at SMA Negeri 3 Tarakan and SMA Tunas Kasih Tarakan, and the students of Class X IPA (Natural Science) from both senior high schools. The data were collected using a questionnaire which was distributed to biology teachers in each school, then were conducted interview and documentation. The result of the study showed that the teachers of SMA Negeri 3 Tarakan accomplished the achievement in aspects of planning 100%, implementation 100%, reporting 100%, attitude assessment 100%, knowledge assessment 100%, and skill assessment 100%, while the teacher of SMA Tunas Kasih Tarakan reached the achievement in aspects of planning 100%, implementation 100%, reporting 100%, attitude assessment 40%, knowledge assessment 100%, and skill assessment 71%. Both teachers had conducted authentic assessment during the learning process which contained the competences of attitude, knowledge, and skill. However, the implementation of authentic assessment had not been fully fulfilled optimally in the aspects of attitude and skill. The constraining factors for the implementation of authentic assessment were : (1) availability of time, (2) availability of worksheet, and (3) avaibility of facilities such as LCD and internet acces. The supporting factors for the implementation of authentic assessment were : (1) students, (2) calassroom.