2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47789I review the recent work on obtaining precise estimates of higher-order corrections in QCD and field theory.Invited talk at the Cracow Epiphany Conference on Spin Effects in Particle Physics, January 9-11, 1998, Cracow, Poland; 16 pages, latex; includes 7 figures; requires appb.sty,epsfig.sty,float.sty,tables.sty (included)High Energy Physics - PhenomenologyHigh Energy Physics - Theorytext