remarkably uniform and nearly all of the data consist of new measurements reduced in a uniform way. Also note that the surveys nicely complement each other: ENEAR galaxies probe high density regions and delineate large-scale structures more sharply; SFI galaxies probe lower density regimes and are more uniformly distributed across the sky. Another important point is that the peculiar velocities in these catalogs are measured using distinct distance estimators based on different observed quantities. Therefore, to take full advantage of these characteristics these samples have been analyzed separately, to test the reproducibility of the results, and combined into the SEcat catalog to produce a fair sample probing a wide range of density regimes. The results of analyses based on these new catalogs of peculiar velocity data are reviewed below and compared to those obtained using Mark III.

Results
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Reconstructed density and velocity fields
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An underlying assumption of all methods used in estimating $\beta$ is that galaxies, even though biased, are fair tracers of the mass distribution. This hypothesis can be, in principle, directly tested by comparing the galaxy density field as derived from redshift surveys and the mass density field reconstructed from peculiar velocity data. POTENT, Wiener Filter[@wf] 