2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45543The consecutive integration over the distinct mass scales ${\cal O}(T),{\cal O}(gT)$ leads to a hierarchy of effective models for the electroweak phase transition. Different techniques for the realisation of such strategy are reviewed. Advantages and difficulties resulting from the use of reduced models are discussed.9 pages latex, no figs., to appear in Procs. of PASCOS/Hopkins 1995 ConferenceHigh Energy Physics - Phenomenologytext