Ph.D Thesis in Computer Science, specifically in the field of Computational Linguistics, written by Oscar Ferrández under the supervision of Dr. Rafael Muñoz Guillena. The author was examined on July 27th, 2009 by a panel formed by Dr. Manuel Palomar (UA), Dr. Andrés Montoyo Guijarro (UA), Dr. Arantza Dı́az de Ilarraza (EHU/UPV), Dr. Luis Alfonso Ureña (UJA) and Dr. Raquel Mart́ınez Unanue (UNED)...