@TechReport{Langdon98,
  author      = "William B Langdon and Riccardo Poli",
  title       = {Why "Building Blocks" Don't Work on Parity Problems},
  institution = {University of Birmingham, School of Computer Science},
  number      = {CSRP-98-17},
  month       = {July},
  year        = {1998},
  email       = {W.B.Langdon@cs.bham.ac.uk, R.Poli@cs.bham.ac.uk},
  file        = {/1998/CSRP-98-17.ps.gz},
  url         = {ftp://ftp.cs.bham.ac.uk/pub/tech-reports/1998/CSRP-98-17.ps.gz},
  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.
                 },
}