Chapter 1 Conceptual Analysis of Abduction

Abduction, or inference to the best explanation, is a form of inference that goes from data describing something to a hypothesis that best explains or accounts for the data. Thus abduction is a kind of theory-forming or interpretive inference. The philosopher and logician Charles Sanders Peirce (1839-1914) contended that there occurs in science and in everyday life a distinctive pattern of reasoning wherein explanatory hypotheses are formed and accepted. He called this kind of reasoning Òabduction.Ó In their popular textbook on artificial intelligence (AI), Charniak and McDermott (1985) characterize abduction variously as modus ponens turned backward, inferring the cause of something, generation of explanations for what we see around us, and inference to the best explanation. They write that medical diagnosis, story understanding, vision, and understanding natural language are all abductive processes. Philosophers have written of Òinference to the best explanationÓ (Harman, 1965) and Òthe explanatory inferenceÓ (Lycan, 1988). Psychologists have found Òexplanation-basedÓ evidence evaluation in the decision-making processes of juries in law courts (Pennington & Hastie, 1988). We take abduction to be a distinctive kind of inference that follows this pattern pretty nearly: