A number of important terms and concepts have been introduced in the introductory sections of this chapter that should now be more formally defined.
What is a typology? A typology is a classification system and a set of decision rules used to differentiate relatively homogeneous groups called subtypes. A subtype is an abstract category organized according to some conceptual, theoretical, and clinical principle. According to one student of clinical subtyping (Millon, 1991), subtypes of complex clinical phenomena are “splendid fictions” because nature was not made to suit the conceptual need for a well-ordered universe. As noted above with typologies of alcoholism, different concepts and categories can be formulated and labeled in a variety of ways, but bear in mind that these labels are not necessarily “realities.” This realization should not discourage one from attempting to make sense of complex clinical phenomena and heterogeneous groups if the primary purpose is kept in mind to benefit people in need and make the most efficient use of resources.
What is a “homeless family”? Although this term appears to be self-evident, it is important to note that “homeless” should include both literal homelessness and families who are doubling up with others by necessity, and “family” should include couples without children, couples with children, and the large category of single parent with children.