Journal of Artificial Intelligence Research 4 (1996) 397-417.
Submitted 12/95; published 5/96.
© 1996 AI Access Foundation and Morgan Kaufmann Publishers. All rights reserved.
Geoffrey I. Webb email@example.com
School of Computing and Mathematics
Geelong, Vic, 3217, Australia.
This paper presents new experimental evidence against the utility of Occam's razor. A systematic procedure is presented for post-processing decision trees produced by C4.5. This procedure was derived by rejecting Occam's razor and instead attending to the assumption that similar objects are likely to belong to the same class. It increases a decision tree's complexity without altering the performance of that tree on the training data from which it is inferred. The resulting more complex decision trees are demonstrated to have, on average, for a variety of common learning tasks, higher predictive accuracy than the less complex original decision trees. This result raises considerable doubt about the utility of Occam's razor as it is commonly applied in modern machine learning.