abstract = "In this paper, we analyse two general-purpose encoding
types, trees and graphs systematically, focusing on
trends over increasingly complex problems. Tree and
graph encodings are similar in application but offer
distinct advantages and disadvantages in genetic
programming. We describe two implementations and
discuss their evolvability. We then compare performance
using symbolic regression on hundreds of random
nonlinear target functions of both 1-dimensional and
8-dimensional cases. Results show the graph encoding
has less bias for bloating solutions but is slower to
converge and deleterious crossovers are more frequent.
The graph encoding however is found to have
computational benefits, suggesting it to be an
advantageous trade-off between regression performance
and computational effort.",
notes = "GECCO-2007 A joint meeting of the sixteenth
international conference on genetic algorithms
(ICGA-2007) and the twelfth annual genetic programming
conference (GP-2007).