Reference: P. Clark and T. Niblett. The CN2 Induction Algorithm. Machine Learning, 3(4):261-283, 1989.

Abstract: Systems for inducing concept descriptions from examples are valuable tools for assisting in the task of knowledge acquisition for expert systems. This paper presents a description and empirical evaluation of a new induction system, CN2. designed for the efficient induction of simple, comprehensible production rules in domains where problems of poor description language and/or noise may be present. Implementations of the CN2, ID3 and AQ algorithms are compared on three medical classification tasks.

PDF: http://www.cs.utexas.edu/users/pclark/papers/cn2.pdf
Compressed postscript: http://www.cs.utexas.edu/users/pclark/papers/cn2.ps.Z.