- Ross Quinlan
John Ross Quinlan is a pioneering
computer science researcher indata mining anddecision theory . He has contributed extensively to the development ofdecision tree algorithms, including inventing the canonical C4.5 and ID3 algorithms. He is currently running the company RuleQuest Research [http://www.rulequest.com] which he founded in 1997.Education
He received his computer science doctorate at the
University of Washington in1968 . He has held positions at theUniversity of Sydney ,University of Technology Sydney , andRAND Corporation .Artificial Intelligence
He is a specialist in
Artificial Intelligence , particularly in the aspect involvingMachine Learning and its application toData Mining . [ [http://ieeexplore.ieee.org/iel4/6088/16304/00754923.pdf?arnumber=754923 Data Mining From an AI Perspective] ]ID3
Ross Quinlan invented the Iterative Dichotomiser 3 (ID3) algorithm which is used to generate decision trees. ID3 follows the principal of
Occam's razor in attempting to create the smallest decision tree possible.C4.5
He then expanded upon the principals 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). The basic structure of the program is:
Check for base cases For each attribute a Find the normalized information gain from splitting on a Let a_best be the attribute with the highest normalized information gain Create a decision node node that splits on a_best recur on the sublists obtained by splitting on a_best and add those nodes as children of node
C5.0
C5.0 which Quinlan is commercially selling is an improvement on C4.5. The advantages are several orders of magnitude faster, memory efficiency, smaller decision trees, Boosting (more accuracy), ability to weight different attributes, and Winnowing (reducing noise).
ee also
*
ID3 algorithm
*C4.5 algorithm
*Data Mining References
External links
* [http://www.rulequest.com/Personal/ Personal homepage]
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