Validitas Buku Ensiklopedia Famili Meliaceae di Kebun Raya Banua Untuk Melatihkan Keterampilan Berpikir Kritis

: In the 21st century education requires students to have 4C skills, one of which is critical thinking skills. Critical thinking skills can be trained in various ways, one of which is using teaching materials. The teaching materials developed in this study are Encyclopedia books. This study aims to describe the content validity of the encyclopedia of the Meliaceae family at Kebun Raya Banua to train students' critical thinking skills. The research is limited only with regard to content validation. This encyclopedia development research used the EDR (Educational Design Research) research method. The object of this research is an encyclopedia book. The subjects of this study were three experts as validators. The results of the validation test are stated in the valid category so that it is feasible as an alternative source of learning.