@inbook{8ae22f3e4dd84d68992692ca27ac5a0d,

title = "Local Search is Underused in Genetic Programming",

abstract = "There are two important limitations of standard tree-based genetic programming (GP). First, GP tends to evolve unnecessarily large programs, what is referred to as bloat. Second, GP uses inefficient search operators that focus on modifying program syntax. The first problem has been studied extensively, with many works proposing bloat control methods. Regarding the second problem, one approach is to use alternative search operators, for instance geometric semantic operators, to improve convergence. In this work, our goal is to experimentally show that both problems can be effectively addressed by incorporating a local search optimizer as an additional search operator. Using real-world problems, we show that this rather simple strategy can improve the convergence and performance of tree-based GP, while also reducing program size. Given these results, a question arises: Why are local search strategies so uncommon in GP? A small survey of popular GP libraries suggests to us that local search is underused in GP systems. We conclude by outlining plausible answers for this question and highlighting future work.",

keywords = "Genetic programming (GP), Evolvability, Local search (optimization), Symbolic regression, Numerical optimization, Bloat, NeuroEvolution of augmenting topologies",

author = "Leonardo Trujillo and Emigdio Z-Flores and Ju{\'a}rez-Smith, {Perla S.} and Pierrick Legrand and Sara Silva and Mauro Castelli and Leonardo Vanneschi and Oliver Sch{\"u}tze and Luis Mu{\~n}oz",

note = "Trujillo, L., Z-Flores, E., Ju{\'a}rez-Smith, P. S., Legrand, P., Silva, S., Castelli, M., ... Mu{\~n}oz, L. (2018). Local Search is Underused in Genetic Programming. In R. Riolo, B. Worzel, B. Goldman, & B. Tozier (Eds.), Genetic Programming Theory and Practice XIV (pp. 119-137). [8] (Genetic and Evolutionary Computation). Springer. https://doi.org/10.1007/978-3-319-97088-2_8",

year = "2018",

month = oct,

day = "25",

doi = "10.1007/978-3-319-97088-2_8",

language = "English",

isbn = "978-3-319-97087-5",

series = "Genetic and Evolutionary Computation",

publisher = "Springer",

pages = "119--137",

editor = "Riolo, {Rick } and Worzel, {Bill } and Brian Goldman and Bill Tozier",

booktitle = "Genetic Programming Theory and Practice XIV",

address = "Netherlands",

}