One Operator, One Landscape
Terry Jones
Santa Fe Institute
1399 Hyde Park Road
Santa Fe, NM 87501, USA
terry@santafe.edu
Abstract
The use of the term "landscape" is increasing rapidly in the
field of evolutionary computation, yet in many cases it remains
poorly, if at all, defined. This situation has perhaps developed
because everyone grasps the imagery immediately, and the questions
that would be asked of a less evocative term do not get asked. This
paper presents an important consequence of a new model of
landscapes. The model is general enough to encompass most of what
computer scientists would call search, though it is not restricted to
either the field or the viewpoint. The consequence is a
"one-operator, one-landscape" view of search algorithms that
is particularly relevant for algorithms that search via the use of
multiple operators, and hence to genetic algorithms and other members
of the evolutionary computing family. Crossover and selection
landscapes are presented as siblings of the traditional mutation
landscape. The model encourages a perspective on search algorithms
that makes a clear division between landscape structures and
navigation upon them. This division is the basis for the design of new
search algorithms that combine elements of existing algorithms, an
example of which is a crossover hillclimber. The model also
establishes a strong connection with the heuristic state space search
algorithms of Artificial Intelligence.
Terry Jones (terry <AT> jon.es)