2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/39775Reliable knowledge of parton distributions at large x is crucial for many searches for new physics signals in the next generation of collider experiments. Although these are generally well determined in the small and medium x range, it has been shown that their uncertainty grows rapidly for x>0.1. We examine the status of the distributions in light of new questions that have been raised about "large-x" parton distributions, as well as recent measurements which have improved the parton uncertainties.LaTeX, 5 pages, 2 figures. Invited talk at 8th International Workshop on Deep Inelastic Scattering and QCD (DIS 2000), Liverpool, England, 25-30 Apr 2000High Energy Physics - Phenomenologytext