The Evolution of Size and Shape

Created by W.Langdon from gp-bibliography.bib Revision:1.4524

  author =       "William B. Langdon and Terry Soule and 
                 Riccardo Poli and James A. Foster",
  title =        "The Evolution of Size and Shape",
  booktitle =    "Advances in Genetic Programming 3",
  publisher =    "MIT Press",
  year =         "1999",
  editor =       "Lee Spector and William B. Langdon and 
                 Una-May O'Reilly and Peter J. Angeline",
  pages =        "163--190",
  chapter =      "8",
  address =      "Cambridge, MA, USA",
  month =        jun,
  keywords =     "genetic algorithms, genetic programming, bloat",
  ISBN =         "0-262-19423-6",
  URL =          "",
  URL =          "",
  abstract =     "The phenomenon of growth in program size in genetic
                 programming populations has been widely reported. In a
                 variety of experiments and static analysis we test the
                 standard protective code explanation and find it to be
                 incomplete. We suggest bloat is primarily due to
                 distribution of fitness in the space of possible
                 programs and because of this, in the absence of bias,
                 it is in general inherent in any search technique using
                 a variable length representation.

                 We investigate the fitness landscape produced by
                 program tree-based genetic operators when acting upon
                 points in the search space. We show bloat in common
                 operators is primarily due to the exponential shape of
                 the underlying search space. Nevertheless we
                 demonstrate new operators with considerably reduced
                 bloating characteristics. We also describe mechanisms
                 whereby bloat arises and relate these back to the shape
                 of the search space. Finally we show our simple random
                 walk entropy increasing model is able to predict the
                 shape of evolved programs.",
  notes =        "AiGP3 See",
  size =         "28 pages",

Genetic Programming entries for William B Langdon Terence Soule Riccardo Poli James A Foster