Next: Introduction
Why ``Building Blocks'' Don't Work on Parity Problems
W. B. Langdon and R. Poli
School of Computer Science
The University of Birmingham,
Birmingham B15 2TT, UK
{W.B.Langdon,R.Poli}@cs.bham.ac.uk
http://www.cs.bham.ac.uk/
wbl, 126 rmp
Tel: +44 (0) 121 414 4791 Fax: +44 (0) 121 414 4281
Technical Report: CSRP-98-17
13 July 1998
Abstract:
We investigate the distribution of performance of
the parity and always-on Boolean functions
given only the appropriate building block.
These problems have ``needle in a haystack'' fitness landscape and so
are unsuitable for genetic programming or other progressive search
techniques.
Theoretical analysis shows in the limit as program size grows
the density of solutions is independent of size but falls
exponentially with number of inputs.
William B Langdon
Mon Jul 13 15:53:27 BST 1998