Induction

In the context of gaining empirical knowledge and doing scientific fieldwork, induction refers to the practice of inferring general claims from regularities observed within a particular body of data. Such general claims are usually delivered as probabilistic judgments or law-like statements. To use an example of the sort frequently given in introductory philosophy textbooks, consider the following: From the fact that the last two hundred pieces of copper I inspected conducted electricity, I infer that in all likelihood the next piece of copper I inspect will also conduct electricity. In the present formulation, this would be a probabilistic judgment, whether the probability is numerically specified or not. Alternatively, one might use the same set of observational data, or evidence, as a basis for advancing the universal claim that all copper (defined by some independent chemical characteristics like molecular structure) is a conductor of electricity. This last formulation would amount to a law-like statement about the general nature of copper in all its past and future manifestations and not just make a forecast about the next sample of copper to be inspected.

Construed in these general terms, induction does not look theoretically troublesome, and practically it seems rather indispensable. After all, the interpretation of empirical data gathered during, say, a pharmaceutical trial carried out to test a newly developed allergy medication for adverse side effects would hardly get off the ground without resorting to some kind of inductive inference. However, this rough-and-ready account of the interpretive situation glosses over various difficulties involved in such a scenario and thus oversimplifies the notion of induction in its theoretical as well as practical aspects. To fully appreciate these different facets, this entry surveys some of the most prominent philosophical inquiries into induction, before spelling out how these critical analyses are relevant for social scientists and communication researchers.