<![CDATA[The research and development about performance assessment on experiment of determining the system type has been done. The performance assessment instrument which has been developed having the characteristics of among others a simple product, efficient, and easy to be used. Based on validation, validator gave an assess to construction, readability, and product suitability aspects in very high criteria with the percentage of them were 93.33%, 86.67%, and 100%, respectively. In other hands, teachers also gave and assess to them aspects in high criteria persentage of them were 73.34%, 80%,, dan 80%, respectively. Base on the result, performance assessment instrument which has been developed was said simple, efficient, and easy to be used.Penelitian dan pengembangan ini telah mengembangkan instrumen asesmen kinerja menentukan jenis-jenis sistem. Instrumen penilaian kinerja yang telah dikembangkan memiliki karakteristik antara lain produk yang sederhana, efisien, dan mudah untuk digunakan. Hasil validasi ahli terhadap aspek konstruksi, keterbacaan, dan keterpakaian produk berturut-turut yaitu 93,33%, 86,67%, dan 100% dengan kriteria sangat tinggi. Tanggapan guru terhadap aspek konstruksi, keterbacaan dan keterpakaian produk berturut-turut yaitu 73,3%, 80%, 80%. Instrumen asesmen kinerja yang telah dikembangkan dikatakan sederhana, efisien, dan mudah untuk digunakan.Kata kunci: instrumen asesmen kinerja, penelitian dan pengembangan, sistem dan lingkungan, termokimia]]>
