Do Various Indices of Galaxy Clustering Describe the Same Physical Property?

From a study of values of indices c 2 , g 2 and s 2 in the statistical reduction method and the k-index in Zwicky's subsequent division method applied to the same population, it is concluded that indices of the same general type of clustering, but formulated in different ways mathematically, sometimes lead to opposite results. The pattern of clustering of galaxies is by no means intrinsically easy to describe. Numerous efforts to obtain a mathematical formulation of clustering that is both clear and close to reality, from the early models of Neyman to sophisticated contemporary methods, have failed to live up to expectations. Expressions like, " single cluster " of galaxies, " super-cluster " , " void " , " filament between clusters " , etc., are among the fuzziest in the astronomical vocabulary, and are not subject to any strict physical or mathematical definition. Another unclear notion is the measure of intensity of clustering. In different descriptive methods, different indices are used. One might expect that indices belonging to different mathematical descriptive