We study the statistics of the experimental eigenfunctions of chaotic and
disordered microwave billiards in terms of the moments of their spatial
distributions, such as the Inverse Participation Ratio (IPR) and
density-density auto-correlation. A path from chaos to disorder is described in
terms of increasing IPR. In the chaotic, ballistic limit, the data correspond
well with universal results from random matrix theory. Deviations from
universal distributions are observed due to disorder induced localization, and
for the weakly disordered case the data are well-described by including finite
conductance and mean free path contributions in the framework of nonlinear
sigma models of supersymetry.Comment: 5 pages + 2 JPG figure