<![CDATA[The purposes of this research were to develop the assessment instrument based on science process skill and to describe teachers response about developed assesment instrument. This research used Research and Development (RD) method. This research was guided by need assesment questionnaire instrument, validations authority, teacher responses instrument. This assessment instrument characteristics was the assessment instrument that measures students' cognitive skills associated with science process. The validation result was obtained percentage on aspects in suitability of content, readability, and construction were 93.75 %; 84,61 %; and 94 %, respectively. The percentages of teacher responses to assessment instrument was obtained on aspects in suitability of content, readability, and construction were 89,37%; 86,15%; and 87,75%. Thus, assessment instruments developed have very high criteria with the average percentage of 90,78 %.Penelitian dan pengembangan ini bertujuan untuk mengembangkan instrumen asesmen berbasis keterampilan proses sains (KPS) dan mendeskripsikan tanggapan guru mengenai instrumen asesmen. Metode yang digunakan dalam penelitian ini adalah Research and Development (RD). Penelititan ini menggunakan instrumen angket analisis kebutuhan, instrumen validasi ahli, instrumen tanggapan guru. Karakteristik instrumen asesmen ini adalah instrumen asesmen yang mengukur ranah kognitif siswa yang berhubungan dengan keterampilan proses sains. Berdasarkan hasil validasi ahli diperoleh persentase asesmen pada aspek kesesuaian isi, keterbacaan, dan konstruksi sebesar 93,75%; 84,61%; dan 94,00%. Persentase tanggapan guru pada aspek uji kesesuaian isi, keterbacaan, dan kontruksi adalah sebesar 89,37%; 86,15%; dan 87,75%. Jadi, instrumen asesmen yang dikembangkan memiliki kriteria sangat tinggi dengan rata-rata persentase sebesar 90,78%.Kata kunci : asesmen, KPS, stoikiometri]]>
