Branches Disciplines have long been a dominant way of knowledge organziation. Traditionally these were the 7 Liberal Arts (Trivium and Quadrivium). As knowledge grew the image of a tree and branches was a basic metaphor in knowledge organization. This led a series of hierarchical, tree structures: Branch Branches of Classes Categories Dsiciplines Fields Divisions (Divisio) Parts (Partitio) These led to further refinements such as sub-classes, subcategories, subdivisions. Some of these divisions were chronological or regional: Movements Schools Some fields such as literature, music, and film eluded such simple hierarchical structures. This led to additional cateegories: Genres Forms More recently, cognitive science has attemopted automated means of arriving at: Categories (same word but different uses than Aristotle) Topics Lists There are also new headings such as: Areas of Study Portals.