ABSTRACT
The principal sources of grounded theory consist both of the data of diverse systematic research and the substantive theories generated from such data. The cumulative design suggests that, besides ethnographic studies, multiple substantive and formal theories are needed to build up, through discovering their relationships, to more inclusive formal theories. The several sources of formal theory can usefully be classified in three ways: grounded in systematic research, ungrounded, or a combination of both grounded and ungrounded. Substantive theories typically have important general relevance and become, almost automatically, springboards or stepping stones to the development of a grounded formal theory. The integration of a dense formal theory is accomplished quite differently than that of a substantive theory. The basic criterion governing the selection of comparison groups for generating theory is their theoretical relevance for furthering the development of emerging categories, properties, hypotheses, and integration of the theory.
