EdGate’s taxonomy, referred to as the Concept Index, is a list of standards-based curricular concepts that has been successfully tested by years of alignment to standards. It is the source by which any piece of content can be directly aligned to all standards in one step! We package the Concept Index by subject with all associated standards. The index for the four core subjects (Language Arts, Math, Science, and Social Studies) includes 1,500 of the top concepts per subject which attains approximately 90% standards coverage. Other subjects are also available.