Kouichi Hirata

Abstract Abduction is a methodology of scientific inquiry. Peirce showed three types of abduction, and expressed them by one syllogism. In computer science, especially in the fields of automated reasoning and machine learning, various researches on abduction or abductive logic have been developed. In order to systematically understand such researches and to clearly discuss abduction, this paper classifies abduction into five types. This new classification is based on an interpretation of the syllogism in abduction and the definitions of hypotheses. We examine various researches on abduction so far developed and show that many researches on abduction can be placed in our classification. Furthermore, we discuss the most essential type of abduction in our classification for logic programming and default logic, and describe Prolog programs for abduction.