  Under the assumption of a void-filled Universe we investigate if the
characteristic scale of voids can be determined from existing surveys. We use
the Voronoi tessellation to create mock surveys and study the properties of the
first zero-crossing of the two-point correlation function for various survey
geometries. Our main conclusion is that the available data sets should be able
to discriminate between 5000 \kms and 12000 \kms voids, if one of these scales
actually characterizes the distribution of galaxies.
