Lexicase selection is a parent selection method that has been shown to improve the problem solving power of genetic programming over a range of problems. Previous work has shown that it can also produce hyperselection events, in which a single individual is selected many more times than other individuals. Here we investigate the role that hyperselection plays in the problem-solving performance of lexicase selection. We run genetic programming on a set of program synthesis benchmark problems using lexicase and tournament selection, confirming that hyperselection occurs significantly more often and more drastically with lexicase selection, which also performs significantly better. We then show results from an experiment indicating that hyperselection is not integral to the problem-solving performance or diversity maintenance observed when using lexicase selection. We conclude that the power of lexicase selection stems from the collection of individuals that it selects, not from the unusual frequencies with which it sometimes selects them.
|Original language||English (US)|
|Title of host publication||GECCO 2016 - Proceedings of the 2016 Genetic and Evolutionary Computation Conference|
|Publisher||Association for Computing Machinery, Inc|
|Number of pages||8|
|State||Published - Jul 20 2016|
|Event||2016 Genetic and Evolutionary Computation Conference, GECCO 2016 - Denver, United States|
Duration: Jul 20 2016 → Jul 24 2016
|Name||GECCO 2016 - Proceedings of the 2016 Genetic and Evolutionary Computation Conference|
|Other||2016 Genetic and Evolutionary Computation Conference, GECCO 2016|
|Period||7/20/16 → 7/24/16|
Bibliographical noteFunding Information:
Thanks to the members of the Hampshire College Computational Intelligence Lab for discussions that helped shape this work and to Josiah Erikson for systems support. This material is based upon work supported by the National Science Foundation under Grants No. 1129139 and 1331283. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation.
- Lexicase selection
- Program synthesis
- Tournament selection