Deduction, induction, and abduction are three basic forms of inference that inform the methodologies of communication research as well as other fields and disciplines. Whereas the most familiar forms are inference from a general principle or law to individual instances (deduction), or from several instances to a law (induction), abduction is an equally important constituent of scholarship, serving to identify possible explanations for a set of observations. Different traditions of communication research can be seen to rely on distinctive variants and combinations of deduction, induction, and abduction.
Aristotle had identified abduction as a type of inference; it was reintroduced in modern philosophy by Charles Sanders Peirce in an 1878 article. An inference can be said to consist of three components – a rule which, when applied to a single case, produces a result or conclusion. These components yield three possible combinations (adapted from Peirce 1992):
DEDUCTION
Rule. All the beans from this bag are white.
Case. These beans are from this bag.
Result. These beans are white.
INDUCTION
Case. These beans are from this bag.
Result. These beans are white.
Rule. All the beans from this bag are white.
ABDUCTION
Result. These beans are white.
Rule. All the beans from this bag are white.
Case. These beans are from this bag.
Strictly speaking, only the deduction is a valid inference. When the rule is applied to the case, the result follows from the meaning of the constituent terms. In the induction, the implication is that, if one examines a sufficient number of beans from the bag in question (cases), one may be willing to conclude that they are all white. The point of the abduction is that it introduces a rule which may explain why one encounters particular facts (white beans) in a particular context (the bean bag). While the bean example is trivial, such a newly devised rule can represent an exceptionally bright idea, as in Sherlock Holmes’s solution of crime mysteries (Sebeok & Umiker-Sebeok 1983) and major scientific discoveries such as Charles Darwin’s conception of the origin of the human species by natural selection.
An Inductive Heritage
Induction has a long heritage in human history and evolution. The capacity for generalizing from single events presumably has been a key instrument of human adaptation and survival. Also commonsense or lay theories (Furnham 1988) that guide people through their everyday activities have important ingredients of induction.
Despite David Hume’s argument, in the mid-1700s, that an induction from “some” to “all” is never logically valid, an inductive ideal of science remained attractive throughout the nineteenth century. Notably, John Stuart Mill’s A system of logic (1843) detailed how inferences could be accumulated in various scientific fields. In the early twentieth century, an inductive ideal of science rose to new prominence in the shape of logical positivism.
Taking its general cue from Mill’s contemporary, Auguste Comte, and his call for a “positive philosophy” that would be nonspeculative and applicable to real human concerns, logical positivism developed into an influential school of thought between the two world wars. Much of the inspiration came from the so-called linguistic turn of philosophy, which took the structure of sentences to correspond to the structure of facts in reality. Logical positivism, further, upheld an absolute distinction not only between facts and values, but between empirical observations and theoretical conceptions of reality. Accordingly, any meaningful statement about the world is either elementary in itself (reducible to sense impressions in a given space and time), or may be decomposed into such elementary propositions, which are either true or false.
Within such a reductionist conception of knowledge, most of the questions of both social scientific and humanistic research fall outside the realm of science. In response, these disciplines and fields have fundamentally questioned the view of science as the identification of universal laws, or context-independent regularities; the grounding of science in elementary sensations; and the requirement that all scientific research proceed according to the same methodological principles (Hammersley 1989, 17). Re-emphasizing deduction and abduction, much contemporary theory of science has specified principles and procedures for producing knowledge concerning communication, culture, and society.
Inductivism does figure prominently in at least two kinds of current communication research. First, probably the majority of all media studies are of the descriptive and administrative (and often commercial-confidential) variety, including marketing studies of media audiences and evaluation research informing industry or government policy decisions. Importantly, although the aim is not to state or test particular theories, the approaches and findings are still theory-loaded (Hanson 1958). Second, grounded theory has advocated generating explanatory categories from the field and its informants – inducing theory from data. This position, in turn, has been questioned since grounded data collection and analysis may be guided by unacknowledged theoretical frameworks.
A Deductive Mainstream
The quantitative mainstream of international communication research is sometimes described as hypothetico-deductive, testing hypotheses that have been deduced from some general theoretical principle. In a first step, deduction ensures that a hypothesis is neither logically inconsistent nor tautological. Next, a relevant hypothesis may contradict or specify an accepted principle, calling for further study. Again, it is deduction that serves to predict what the researcher will find under specified circumstances. If, finally, the findings correspond to the prediction, the hypothesis is confirmed.
Confirmation, however, does not equal verification. The hypothetico-deductive approach, as elaborated especially in Popper’s (1972) critical rationalism, stipulates that scientists must seek to falsify their hypotheses. Only if falsification fails is one justified in still holding the hypothesis, and only preliminarily. Further studies may end up falsifying it – which readmits inductivism through the backdoor.
In formal terms, the prototypical quantitative study will pose a null hypothesis, which suggests that any relations between the variables, as anticipated by the theory and documented by the data, are due to chance fluctuations or random error. If this is the case, as defined by a conventionally agreed level of probability, the original hypothesis has been falsified. The quantitative research process thus operates on a principle of deduction, even if the mechanisms in question are ascertained in probabilistic terms (see Hempel & Oppenheim 1988, 13 –18).
The practice of critical rationalism has been challenged for not living up to its principles. A key problem relates to the notion of probability, which gradually acquired an ambiguous meaning in modern philosophy and empirical sciences (Hacking 1975). On the one hand, stochastic probability has to do with stable relative frequencies; the purpose is to rule out, beyond a reasonable doubt, that the particular configuration of empirical data could have occurred by chance (the null hypothesis). Epistemological probability, on the other hand, concerns “the degree of belief warranted by evidence” (Hacking 1975, 1). The distinction is sometimes summed up in the dictum that “correlation does not equal causation.” In other words, statistical measurements do not in themselves warrant conclusions about causality and other empirical phenomena. Ritchie (1999), for one, suggested that much current empirical media research fails on this crucial point. The fact that the null hypothesis is sufficiently improbable (statistically) is mistaken for evidence that a specific alternative hypothesis, namely, the one deduced in the study, is more probable (epistemologically). The logic of hypothesis testing, then, may contribute to a conflation of two distinct levels of scientific analysis and argument.
An Abductive Substream
Following the demise of positivism as well as other inductivism, qualitative and interpretive approaches to research have sought to specify an alternative to the hypotheticodeductive model. In opposition to Hempel and Oppenheim’s (1988) “covering-law model,” Dray (1957) argued that historical events cannot be examined as a variant of natural events (which may all be “covered” by one law), but require a different type of “rational explanation.” In another influential contribution, Danto (1965) suggested that narratives provide a model for studying historical events and human actions. And Ginzburg (1989) identified an “evidential paradigm” in Sigmund Freud’s and Sherlock Holmes’s uncovering of underlying structures, respectively in dreams and crimes.
While no consensus comparable to the hypothetico-deductive model has yet emerged in communication research, abduction presents itself as a major candidate for a qualitative theory of science. Since Peirce’s early formulation, its relevance has occasionally been considered in both philosophy and other disciplines, including mainstream sociology (Merton 1968, 158). It was reasserted by, among others, Hanson (1958) as part of the post-1945 questioning of both inductive and hypothetico-deductive prototypes of research. More recently, abduction has been reintroduced to social and cultural research, as an alternative to the inductivist self-understanding of grounded theory (Alvesson & Sköldberg 2000), as a strategy of interpretive social science (Blaikie 1993), and as a distinctive characteristic of qualitative media research (Jensen 1995).
In qualitative research projects, the category of abductive inference can explicate and formalize various contextual and empathetic forms of interpretation. One quality of formalization is that it facilitates a systematic comparison of different kinds of reasoning in empirical research. Abduction is at the core of that interchange between researcher and informants that serves to establish – infer – relevant categories and concepts. Qualitative studies gain a resource, first, for structuring key moments of the analytical process and, second, for deciding who (informants, researchers, both) originates which abductions.
In conclusion, the three types of inference point to several different types of relationship between empirical analysis and theory development, In this regard, two main varieties of media and communication research can be identified – hypothetico-deductive reasoning in combination with quantitative data analysis, and abductive reasoning employing qualitative data analysis. And yet many, perhaps most, actual research projects include aspects of abduction, deduction, as well as induction in configurations still to be explored in further research. To exemplify, the prototypical form of social scientific study departs from a relatively specific hypothesis, as derived from a more general premise (deduction), which is tested against a large number of concrete instances (induction). The findings may be only partly in accordance with the hypothesis, giving rise to a new rule (abduction) to be investigated in further research. The original premise of the study might itself have been the outcome of a bright idea or bold conjecture – abduction.
References:
- Alvesson, M., & Sköldberg, K. (2000). Reflexive methodology: New vistas for qualitative research. London: Sage.
- Blaikie, N. (1993). Approaches to social enquiry. Cambridge: Polity.
- Danto, A. C. (1965). Analytical philosophy of history. Cambridge: Cambridge University Press.
- Dray, W. (1957). Laws and explanation in history. Oxford: Oxford University Press.
- Furnham, A. F. (1988). Lay theories: Everyday understanding of problems in the social sciences. Oxford: Pergamon.
- Ginzburg, C. (1989). Clues: Roots for an evidential paradigm. In C. Ginzburg (ed.), Clues, myths, and the historical method. Baltimore, MD: Johns Hopkins University Press, pp. 96 –125.
- Hacking, I. (1975). The emergence of probability. Cambridge: Cambridge University Press.
- Hammersley, M. (1989). The dilemma of qualitative method: Herbert Blumer and the Chicago tradition. London: Routledge.
- Hanson, N. R. (1958). Patterns of discovery: An inquiry into the conceptual foundations of science. Cambridge: Cambridge University Press.
- Hempel, C. G., & Oppenheim, P. (1988). Studies in the logic of explanation. In J. Pitt (ed.), Theories of explanation. New York: Oxford University Press, pp. 9 – 50.
- Jensen, K. B. (1995). The social semiotics of mass communication. London: Sage.
- Merton, R. K. (1968). Social theory and social structure, enlarged edn. New York: Free Press.
- Peirce, C. S. (1992). Deduction, induction, and hypothesis. In C. S. Peirce (ed.), The essential Peirce. Bloomington, IN: Indiana University Press, pp. 186 –199.
- Popper, K. R. (1972). The logic of scientific discovery. London: Hutchinson. (Original work published 1934).
- Ritchie, D. (1999). Probably, probably not: Rhetoric and interpretation in communication research. Paper presented at the International Communication Association Conference, San Francisco.
- Sebeok, T. A., & Umiker-Sebeok, J. (1983). “You know my method”: A juxtaposition of Charles S. Peirce and Sherlock Holmes. In U. Eco & T. A. Sebeok (eds.), The sign of three. Bloomington, IN: Indiana University Press, pp. 11–54.
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