2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44883These are three lectures given at the ``Lake Louise Winter Institute", (Lake Louise Canada, Feb 1993). A pedagogical introduction is given to attempts to formulate a more fundamental theory of elementary particles than that provided by the standard model. After a review of the basic elements of the standard model, its unsatisfactory features, and ideas to modify them will be discussed. An introduction to Technicolour, t-quark condensates, supersymmetric models, GUT's and a brief comment on composite models follow.48 pages, UCLA-93-TEP-33High Energy Physics - Phenomenologytext