- author = "Edwin D. {de Jong} and Jordan B. Pollack",
- title = "Multi-Objective Methods for Tree Size Control",
- journal = "Genetic Programming and Evolvable Machines",
- year = "2003",
- volume = "4",
- number = "3",
- pages = "211--233",
- month = sep,
- keywords = "genetic algorithms, genetic programming, variable size representations, bloat, code growth, multi-objective optimization, Pareto optimality, interpretability",
- ISSN = "1389-2576",
-
URL = "
http://www.cs.uu.nl/~dejong/publications/bloat.ps",
-
URL = "
http://www.cs.uu.nl/~dejong/index.html#bloatgpem",
-
DOI = "
doi:10.1023/A:1025122906870",
-
abstract = "Variable length methods for evolutionary computation
can lead to a progressive and mainly unnecessary growth
of individuals, known as bloat. First, we propose to
measure performance in genetic programming as a
function of the number of nodes, rather than trees,
that have been evaluated. Evolutionary Multi-Objective
Optimisation (EMOO) constitutes a principled way to
optimise both size and fitness and may provide
parameterless size control. Reportedly, its use can
also lead to minimisation of size at the expense of
fitness. We replicate this problem, and an empirical
analysis suggests that multi-objective size control
particularly requires diversity maintenance.
Experiments support this explanation.
The multi-objective approach is compared to genetic programming without size control on the 11-multiplexer, 6-parity, and a symbolic regression problem. On all three test problems, the method greatly reduces bloat and significantly improves fitness as a function of computational expense. Using the FOCUS algorithm, multi-objective size control is combined with active pursuit of diversity, and hypothesised minimum-size solutions to 3-, 4- and 5-parity are found. The solutions thus found are furthermore easily interpretable. When combined with diversity maintenance, EMOO can provide an adequate and parameterless approach to size control in variable length evolution.",
-
notes = "Article ID: 5141122
Tue, 23 Mar 2004 01:22:36 +0100 See erratum in issue 5:1
Initial drop in size. 5-Parity given XOR!",
