2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45837The uncertainties in the perturbative and higher twist corrections to the sum rules for $Γ_{p,n}$ are analyzed. The theoretical predictions for $Γ_{p,n}$ are compared with the whole set of experimental data and the restrictions on theoretical uncertainties was obtained. Suggestions for future experiments are given.12 pages, LATEX, no figures, talk at the Workshop "Prospects on Spin Physics at HERAHigh Energy Physics - Phenomenologytext