Over the last years management of legal information has been signiﬁ-
cantly inﬂuenced by formalized and shared knowledge modelling, organized
in thesauri, taxonomies, semantic networks or ontologies. In particular, le-
gal reasoning, advanced semantic and cross-language legal information re-
trieval, legal drafting and document classiﬁcation, have proved to be fertile
areas where knowledge modelling is successfully applied.
Legal ontologies usually play the role of shared vocabularies as well as
formal conceptualisation of legal notions. They often stand in the tradition
of legal theory and philosophy, but may be grounded in common sense as
Legal ontologies are usually used in different applications as multilingual
document annotation and drafting, multilingual legal information retrieval,
legal reasoning, case-based reasoning, legal assessment, legal concepts com-
parison and harmonization. Moreover the ways in which ontologies are
developed and used (as either bottom-up or top-down, hand-crafted or auto-
matically, or semi-automatically, constructed) is a matter of wide discussion
in the legal information scientiﬁc community.
This special issue of the “Informatica e Diritto” Journal on Legal On-
tologies and Artiﬁcial Intelligence Techniques aims to offer an overview of
theories and well-founded applications that combine Legal Ontologies and
AI techniques, with regard both to theories and implementations. It in-
cludes revised versions of the contributions presented at the fourth edition
of the Workshop on Legal Ontologies and Artiﬁcial Intelligence Techniques
(LOAIT) held on July 7th, 2010 in Fiesole (Italy), in conjunction with Deon
The ﬁrst three editions of the LOAIT Workshop, held in conjunction
with ICAIL Conference2(2005 – Bologna, 2007 – San Francisco, 2009 –
Barcelona), provided valuable opportunities for researchers and practition-
ers in Artiﬁcial Intelligence and Law to discuss problems, exchange informa-
tion and compare perspectives on legal ontologies and their use.
A selection of papers of LOAIT ’07 were published in the volume J.
Breuker, P. Casanovas, M. Klein, E. Francesconi (eds.), Law, Ontologies and
110th International Conference on Deontic Logic in Computer Science.
2International Conference on Artiﬁcial Intelligence and Law.