Theories are perspectives with which people make sense of their world experiences. Formally, a theory is a coherent group of assumptions put forth to explain the relationship between two or more observable facts. John Clancy calls such perspectives “invisible powers” to emphasize several crucial uses of theories, the “unseen” ways in which we approach our world. First, theories provide a stable focus for understanding what we experience. A theory provides criteria for determining what is relevant. To Henry Ford, a large and compliant work force was one relevant factor as he theorized about his business. In other words, his theory of management included, among other things, this assumption about the supply of labor. Second, theories enable us to communicate efficiently and thus move into more and more complex relationships with other people. Imagine the frustration you would encounter if, in dealing with other people, you always had to define even the most basic assumptions you make abo