Ross Quinlan
Encyclopedia
John Ross Quinlan is a computer science
researcher in data mining
and decision theory
. He has contributed extensively to the development of decision tree
algorithms, including inventing the canonical C4.5
and ID3
algorithms. He is currently running the company RuleQuest Research which he founded in 1997.
in 1965 and his computer science doctorate at the University of Washington
in 1968. He has held positions at the University of Sydney
, University of Technology Sydney, and RAND Corporation.
, particularly in the aspect involving machine learning
and its application to data mining
.
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 improved: discrete and continuous attributes, missing attribute values, attributes with differing costs, pruning trees (replacing irrelevant branches with leaf nodes).
) 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).
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
researcher in data mining
Data mining
Data mining , a relatively young and interdisciplinary field of computer science is the process of discovering new patterns from large data sets involving methods at the intersection of artificial intelligence, machine learning, statistics and database systems...
and decision theory
Decision theory
Decision theory in economics, psychology, philosophy, mathematics, and statistics is concerned with identifying the values, uncertainties and other issues relevant in a given decision, its rationality, and the resulting optimal decision...
. He has contributed extensively to the development of decision tree
Decision tree
A decision tree is a decision support tool that uses a tree-like graph or model of decisions and their possible consequences, including chance event outcomes, resource costs, and utility. It is one way to display an algorithm. Decision trees are commonly used in operations research, specifically...
algorithms, including inventing the canonical C4.5
C4.5 algorithm
C4.5 is an algorithm used to generate a decision tree developed by Ross Quinlan. C4.5 is an extension of Quinlan's earlier ID3 algorithm. The decision trees generated by C4.5 can be used for classification, and for this reason, C4.5 is often referred to as a statistical classifier.-Algorithm:C4.5...
and ID3
ID3 algorithm
In decision tree learning, ID3 is an algorithm used to generate a decision tree invented by Ross Quinlan. ID3 is the precursor to the C4.5 algorithm.-Algorithm:The ID3 algorithm can be summarized as follows:...
algorithms. He is currently running the company RuleQuest Research which he founded in 1997.
Education
He received his BSc degree in Physics and Computing from the University of SydneyUniversity of Sydney
The University of Sydney is a public university located in Sydney, New South Wales. The main campus spreads across the suburbs of Camperdown and Darlington on the southwestern outskirts of the Sydney CBD. Founded in 1850, it is the oldest university in Australia and Oceania...
in 1965 and his computer science doctorate at the University of Washington
University of Washington
University of Washington is a public research university, founded in 1861 in Seattle, Washington, United States. The UW is the largest university in the Northwest and the oldest public university on the West Coast. The university has three campuses, with its largest campus in the University...
in 1968. He has held positions at the University of Sydney
University of Sydney
The University of Sydney is a public university located in Sydney, New South Wales. The main campus spreads across the suburbs of Camperdown and Darlington on the southwestern outskirts of the Sydney CBD. Founded in 1850, it is the oldest university in Australia and Oceania...
, University of Technology Sydney, and RAND Corporation.
Artificial intelligence
Quinlan is a specialist in artificial intelligenceArtificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
, particularly in the aspect involving machine learning
Machine learning
Machine learning, a branch of artificial intelligence, is a scientific discipline concerned with the design and development of algorithms that allow computers to evolve behaviors based on empirical data, such as from sensor data or databases...
and its application to data mining
Data mining
Data mining , a relatively young and interdisciplinary field of computer science is the process of discovering new patterns from large data sets involving methods at the intersection of artificial intelligence, machine learning, statistics and database systems...
.
ID3
Ross Quinlan invented the Iterative Dichotomiser 3 (ID3) algorithmID3 algorithm
In decision tree learning, ID3 is an algorithm used to generate a decision tree invented by Ross Quinlan. ID3 is the precursor to the C4.5 algorithm.-Algorithm:The ID3 algorithm can be summarized as follows:...
which is used to generate decision trees. ID3 follows the principle of Occam's razor
Occam's razor
Occam's razor, also known as Ockham's razor, and sometimes expressed in Latin as lex parsimoniae , is a principle that generally recommends from among competing hypotheses selecting the one that makes the fewest new assumptions.-Overview:The principle is often summarized as "simpler explanations...
in attempting to create the smallest decision tree possible.
C4.5
He then expanded upon the principles used in ID3 to create C4.5C4.5 algorithm
C4.5 is an algorithm used to generate a decision tree developed by Ross Quinlan. C4.5 is an extension of Quinlan's earlier ID3 algorithm. The decision trees generated by C4.5 can be used for classification, and for this reason, C4.5 is often referred to as a statistical classifier.-Algorithm: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 LicenseGNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
) 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).