Tag-Based Modularity in Tree-Based Genetic Programming

Several techniques have been developed for allowing genetic programming systems to produce programs that make use of subroutines, macros, and other modular program structures. A recently proposed technique, based on the “tagging” and tag-based retrieval of blocks of code, has shown novel and desirable features, but this was demonstrated only within the context of the PushGP genetic programming system. Following a suggestion in the GECCO-2011 publication on this technique, we show here how tag-based modules can be incorporated into a more standard tree-based genetic programming system. We describe the technique in detail along with some possible extensions, outline arguments for its simplicity and potential power, and present results obtained using the technique on problems for which other modularization techniques have been shown to be useful. The results are mixed; substantial benefits are seen on the lawnmower problem but not on the Boolean even-4-parity problem. We discuss the observed results and directions for future research.

In Proceedings of the Genetic and Evolutionary Computation Conference (GECCO-2012)