SSA could not be possible without the generous support of Drs. Herbert A. and Betty Lou Lubs and the Science, Society, and the Arts Research Conference Endowment. We are deeply grateful!
Lexicase is a parent selection method developed for use in genetic programming. Lexicase selection utilizes a randomized order of test cases and the entire population. The algorithm looks at the first test case in the randomized list and keeps only the member of the population that performed the best on that test case, and discards the rest. Then using this smaller niche of the population, lexicase selection looks at the next case and in the list and again only keeps the individuals that perform the best on this test case. This process continues until either one individual is left, or a group of individuals that performed the same on each error vector, in that case a random individual from that group is chosen. The individual that remains after lexicase selection is used as a parent to breed individuals for the next generation. This project looks at ways of improving lexicase.
