HOW CAN WE MEASURE A CORRELATION LENGTH OF 5-10 MPC WHEN OBSERVATIONSSHOW STRUCTURES EXTENDED OVER 150 MPC

We have analysed the statistical properties of the redshift samples av ailable in the LEDA database. We find that galaxies in this sample sho w very well defined fractal long-range correlation with dimension D ap proximate to 2. We have studied the behaviour of the so-called ''corre lation length'' r(0) (xi(r(0)) = 1) finding a clear dependence on the sample depth, We have done some test to check the statistical robustne ss of these results with respect to the incompleteness of the sample. We find that the correlation properties are stable up to r similar to 150 Mpc, that is the maximum depth in which significant all-sky observ ations are available.