Case-based reasoning, analogical reasoning, and interpolation eatrice Fuchs, Jean Lieber, Laurent Miclet, Alain Mille, Amedeo Napoli, Henri Prade, and Gilles Richard Abstract This chapter presents several types of reasoning based on analogy and similarity. Case-based reasoning, presented in Section 2, consists in searching a case (where a case represents a problem-solving episode) similar to the problem to be solved and to adapt it to solve this problem. Section 3 is devoted to analogical reasoning and to recent developments based on analogical proportion. Interpolative reasoning, presented in Section 4 in the formal setting of fuzzy set representations, is another form of similarity-based reasoning. eatrice Fuchs Univ Lyon, IAE-Universit´ e Lyon 3, CNRS, LIRIS, F-69372 Lyon Cedex 08, e-mail: beatrice.fuchs@liris.cnrs.fr Jean Lieber Universit´ e de Lorraine, CNRS, Inria, LORIA, F-54000 Nancy, France, e-mail: jean.lieber@ loria.fr Laurent Miclet IRISA, 22300 Lannion, e-mail: laurent.miclet@gmail.com Alain Mille Univ Lyon1, CNRS, LIRIS UMR 5205, F-69622 Villeurbanne, e-mail: alain.mille@liris.cnrs.fr Amedeo Napoli Universit´ e de Lorraine, CNRS, Inria, LORIA, F-54000 Nancy, France, e-mail: amedeo. napoli@loria.fr Henri Prade IRIT, CNRS & Universit´ e, 31062 Toulouse cedex 9, France,e-mail: prade@irit.fr Gilles Richard IRIT, CNRS & Universit´ e, 31062 Toulouse cedex 9, France,e-mail: richard@irit.fr 1