By Steve Borgatti
Discussion drawn from:
* Glaser and Strauss. 1967. The Discovery of Grounded Theory.
* Strauss and Corbin. 1990. Basics of Qualitative Research.
Goals and Perspective
The phrase "grounded theory" refers to theory that is developed inductively from a corpus of data. If done well, this means that the resulting theory at least fits one dataset perfectly. This contrasts with theory derived deductively from grand theory, without the help of data, and which could therefore turn out to fit no data at all.
Grounded theory takes a case rather than variable perspective, although the distinction is nearly impossible to draw. This means in part that the researcher takes different cases to be wholes, in which the variables interact as a unit to produce certain outcomes. A case-oriented perspective tends to assume that variables interact in complex ways, and is suspicious of simple additive models, such as ANOVA with main effects only.
Part and parcel of the case-orientation is a comparative orientation. Cases similar on many variables but with different outcomes are compared to see where the key causal differences may lie. This is based on John Stuart Mills' (1843, A system of logic: Ratiocinative and Inductive) method of differences -- essentially the use of (natural) experimental design. Similarly, cases that have the same outcome are examined to see which conditions they all have in common, thereby revealing necessary causes.
The grounded theory approach, particularly the way Strauss develops it, consists of a set of steps whose careful execution is thought to "guarantee" a good theory as the outcome. Strauss would say that the quality of a theory can be evaluated by the process by which a theory is constructed. (This contrasts with the scientific perspective that how you generate a theory, whether through dreams, analogies or dumb luck, is irrelevant: the quality of a theory is determined by its ability to explain new data.)
Although not part of the grounded theory rhetoric, it is apparent that grounded theorists are concerned with or largely influenced by emic understandings of the world: they use categories drawn from respondents themselves and tend to focus on making implicit belief systems explicit.
The basic idea of the grounded theory approach is to read (and re-read) a textual database (such as a corpus of field notes) and "discover" or label variables (called categories, concepts and properties) and their interrelationships. The ability to perceive variables and relationships is termed "theoretical sensitivity" and is affected by a number of things including one's reading of the literature and one's use of techniques designed to enhance sensitivity.
Of course, the data do not have to be literally textual -- they could be observations of behavior, such as interactions and events in a restaurant. Often they are in the form of field notes, which are like diary entries. An example is here.