These methods use the mean motions induced by the large-scale mass distributions on scales of several megaparsecs and above. They are based on GI in the linear regime and approximate extensions into the mildly-nonlinear regime. The different matter contributions to m are relevant, such as ``cold'' and ``hot'' dark matter (see  for a review), but the cosmological constant is not involved. The statistical nature of the initial fluctuations has to be specified in some cases; it is commonly assumed to be a Gaussian random field. The initial fluctuation power spectrum is characterized by the power index n on large scales, by a specific shape (e.g., as predicted by CDM theory), and by its amplitude, e.g., via 8, the rms fluctuation in top-hat spheres of radius 8 h-1Mpc. Galaxy biasing is expected to enter in a simpler manner on these larger scales, but is still an important unknown. In the common simplified treatments it is modeled as a linear biasing relation between the density fluctuations of galaxies and mass, g = b , with different biasing parameters for different galaxy types: biras, bopt, etc. However, non-trivial properties of the biasing scheme may be important.