Abstract: Simplicity is used in curve-fitting and can be illustrated by Goodman's ‘new riddle of induction.’ Taking the simplicity of a hypothesis to depend entirely on the simplicity of the way it is represented does not work, because simplicity of representation is too dependent on the method of representation, and any hypothesis can be represented simply. An alternative ‘semantic’ theory also has problems. A ‘computational’ theory is defended that considers how easy it is to use a hypothesis to get answers to questions in which one is interested.

Keywords: curve-fitting, Nelson Goodman, grue, induction, new riddle of induction, pragmatism, simplicity,