and also known as domains.1 Each domain, such as Abilities, Generalized Work Activities, and Tasks, is made up of the most specific information items in the taxonomy, called descriptors. Because these domains are also taxonomies, they are also referred to as descriptor taxonomies.
Each domain is organized hierarchically. For example, the Abilities domain includes three levels. The highest or most general level is comprised of four categories: cognitive, psychomotor, physical, and sensory (U.S. Department of Labor, 2008). Each of these four groups of abilities includes two levels of more specific descriptors (see Appendix B for the full hierarchy of domains and detailed descriptors). The six broad domains and the detailed domains they contain are described briefly below (some detailed domains are discussed more thoroughly in Chapter 2).