Quinlan is a specialist in
artificial intelligence, particularly in the aspect involving
machine learning and its application to
data mining. He is a Founding Fellow of the
Association for the Advancement of Artificial Intelligence.
ID3 Ross Quinlan invented the
Iterative Dichotomiser 3 (ID3) algorithm which is used to generate decision trees. ID3 follows the principle of
Occam's razor in attempting to create the smallest decision tree possible.
C4.5 He then expanded upon the principles used in ID3 to create
C4.5. C4.5 improved: discrete and continuous attributes, missing attribute values, attributes with differing costs, pruning trees (replacing irrelevant branches with leaf nodes).
C5.0 C5.0, which Quinlan is commercially selling (single-threaded version is distributed under the terms of the
GNU General Public License), is an improvement on C4.5. The advantages are speed (several orders of magnitude faster), memory efficiency, smaller decision trees, boosting (more accuracy), ability to weight different attributes, and winnowing (reducing noise). ==Selected works==