Resource-limited Genetic Programming: Replacing tree depth limits

We propose replacing the traditional tree depth limit in Genetic Programming by a single limit on the amount of resources available to the whole population, where resources are the tree nodes. The resource-limited technique removes the disadvantages of using depth limits at the individual level, while introducing automatic population resizing, a natural side-effect of using an approach at the population level. The results show that the replacement of individual depth limits by a population resource limit can be done without impairing performance, thus validating this first and important step towards a new approach to improving the efficiency of GP.