In a group devoted to community-based research, we were discussing the tendency of academics to seek “generalizable” knowledge, while community-based groups want knowledge that has immediate significance to their own circumstances. That difference can generate conflicts over priorities and objectives. Scholars and community leaders may disagree about what projects should be funded, how time and effort should be spent, and even the ethics of research on human subjects. For example, NIH says, “The goal of clinical research is to develop generalizable knowledge that improves human health or increases understanding of human biology.” But a community group may want to find out whether their kids have a well-understood disease. They may see that as “research.”

What is generalizable knowledge? I think generalizability comes in many forms, each playing a different role in each discipline. That makes the tension between scholarly priorities and the needs of community groups complex. The situation will be very different depending on whether the scholar in question is an epidemiologist, an ethnographer, or a theologian.

Statistical generalization means applying a finding from a given population to other populations. If smoking increases the prevalence of emphysema in Somerville, MA, will that also be true in Boston or in Beijing? Widely applicable findings are more useful than narrower findings. However, people obstinately vary, and if a finding does not generalize, it can still be valuable for the population in which it was found. Thus community groups and academics only differ in the relative value they place on statistical generalizability.

Theoretical generalization means developing or contributing to theoretical frameworks that apply in other situations than the one being studied. A theory can be predominantly explanatory or predictive, like Keynes’ theory that excessive saving causes recessions. Or a theory can be predominantly moral/normative, like Keynes’ theory that the state ought to stimulate economies to increase employment. (This implies that the state has the right and the obligation to intervene.) In my view, almost all explanatory theories about people have normative elements, and vice-versa; but certainly the emphasis varies. In any case, theories must generalize: you can’t have a new theory for each case. You can, however, resist theorizing because it overgeneralizes. Or you can resist spending time on theory because you have a program to run. (Yet programs always have their own theories.)

Methodological generalization means developing or demonstrating a method that others can use in different contexts. Methodological innovations can range from highly practical new medical techniques to essays like Clifford Geertz’ “Deep Play: Notes on the Balinese Cockfight.” We do not read that piece because we are eager to understand cockfights in Bali; we read it to learn and debate the method of “thick description,” which we might apply in other settings. Academics value methodological innovation; practitioners rarely care.

Interpretive generalization. Interpreters of texts, images, events, rituals, and dreams describe the particular objects in ways that convey their form, context, and purpose. Sensitive interpretation resists generalization–but not completely. As Geertz notes:

The besetting sin of interpretive approaches to anything —literature, dreams, symptoms, culture—is that they tend to resist, or to be permitted to resist, conceptual articulation and thus to escape systematic modes of assessment. You either grasp an interpretation or you do not, see the point of it or you do not, accept it or you do not. [But] this just will not do. There is no reason why the conceptual structure of a cultural interpretation should be any less formulable, and thus less susceptible to explicit canons of appraisal, than that of, say, a biological observation or a physical experiment.

Indeed, ethnographers and humanists do generalize from their interpretations of particular objects, although, as Geertz concedes, theory based on interpretation should “stay rather closer to the ground than tends to be the case in sciences more able to give themselves over to imaginative abstraction.”

Political generalizability means using a case to achieve some kind of legal or administrative change that affects other people in other places. Some would say that policies should always reflect statistical and theoretical generalities. The law should treat like cases alike; hard cases make bad law. Those maxims suggest that we should first find general patterns through research, and then make policy fit the patterns. But I think sometimes good laws come straight from dramatic cases, which suffice to demonstrate valid points about justice.