- author = "Hammad Majeed and Conor Ryan",
- title = "A Less Destructive, Context-aware Crossover Operator for {GP}",
- editor = "Pierre Collet and Marco Tomassini and Marc Ebner and Steven Gustafson and Anik\'o Ek\'art",
- booktitle = "Proceedings of the 9th European Conference on Genetic Programming",
- publisher = "Springer",
- series = "Lecture Notes in Computer Science",
- volume = "3905",
- year = "2006",
- address = "Budapest, Hungary",
- month = "10 - 12 " # apr,
- organisation = "EvoNet",
- keywords = "genetic algorithms, genetic programming, steepest ascent crossover hill climbing",
- ISBN = "3-540-33143-3",
- pages = "36--48",
-
DOI = "
doi:10.1007/11729976_4",
- bibsource = "DBLP, http://dblp.uni-trier.de",
-
abstract = "Standard GP crossover is widely accepted as being a
largely {\em destructive} operator, creating many poor
offspring in the search for better ones. One of the
major reasons for its destructiveness is its disrespect
for the context of swapped subtrees in their respective
parent trees when creating offspring. At times, this
hampers GP's performance considerably, and results in
populations with {\em low} average fitness values.
Many attempts have been made to make it a more constructive crossover, mostly by preserving the context of the selected subtree in the offspring. Although successful at preserving context, none of these methods provide the opportunity to discover new and better contexts for exchanged subtrees.
We introduce a context-aware crossover operator which operates by identifying all possible contexts for a subtree, and evaluating each of them. The context that produces the highest fitness is used to create a child which is then passed into the next generation.
We have tested its performance on many benchmark problems. It has shown better results than the standard GP crossover operator, using either the same number or fewer individual evaluations. Furthermore, the average fitness of populations using this scheme improves considerably, and programs produced in this way are much smaller than those produced using standard crossover.",
-
notes = "Part of \cite{collet:2006:GP} EuroGP'2006 held in
conjunction with EvoCOP2006 and
EvoWorkshops2006.
Variation in operator frequencies from beginning to end of GP run.",
