UFO-L: A Core Ontology of Legal Concepts Built from a Legal Relations Perspective Cristine Griffo Ontology & Conceptual Modeling Research Group (NEMO), Universidade Federal do Espírito Santo, Vitória-ES, Brazil 1 RESEARCH PROBLEM Computer and Law is a transdisciplinary research field, which has received increasing attention from researchers in the past twenty-five years (Bench- Capon, T. et al, 2012). The problem of presenting the legal domain has been investigated in different perspectives by researchers, such as (Stamper, 1977), (Hafner, 1980), and (McCarty 1989), one of them is the ontological perspective. From NORMA proposed by (Stamper, 1991) to JudO ontology used in the Judiciary Framework proposed by (Ceci, 2013) and to LOTED2 proposed by (Distinto et al., 2014), ontologies have been used as a means of representing legal concepts. Specifically, there are some kind of ontologies called legal core ontologies (LCO), which represent generic legal concepts (e.g. legal norm, legal fact, and legal relation), usable in different legal domains. Some examples of legal core ontologies are: FBO proposed by (Kralingen, 1997), FOLaw proposed by (Valente, 1995), Core Legal Ontology (CLO) proposed by (Gangemi, 2007), and LRI-Core built by Leibiniz Centre for Law Research Group (Breuker and Hoekstra, 2004b). Ontologies are a response for the paradigm shift, from static data storage in databases disconnected to Linked Data and Semantic Web (Isotani and Bittencourt, n.d), (Kuhn et al. 2014). Specifically, the use of core ontologies in complex domains, such as the legal domain, allows: 1) the reusability of generic concepts and semantic interoperability; 2) the expressiveness gain in languages based on ontologies, as well as clarity and correctness of the represented domain (Guizzardi, 2005). Despite the efforts of researchers in the search for a computational solution that satisfactorily represent the legal domain, frequently research has not taken into account the use of legal theories, resulting in a gap between the conceptualizations that are typically considered in the areas of Computer Science and the study of the Law. In a preview systematic mapping of the literature on legal core ontologies, from 128 studies selected, in the time interval of 1995-2014, we have found out that only 35 (approx. 27%) used primary sources of legal theories; 44 studies (approx. 34%) used indirect sources (e.g. use a LCO based on a legal theory to build a domain ontology); and 49 studies (approx. 38%) did not use any legal theory as primary source (Griffo et al., 2015a). This gap has been the subject of several papers, among them, the paper Artificial Intelligence and Legal Theory at Law Schools written by Gordon (Gordon, 2005), who suggested the introduction of an interdisciplinary subject in law schools. Also, in the paper Ontologies: the Missing link between Legal Theory and AI & Law, (Valente and Breuker, 1994) ontologies are presented as a missing link between AI & Law, emphasizing the importance of using legal theories as basis in Computer and Law research. Recently, Casanovas (Casanovas, 2012) wrote about the remaining gap, pointing out the nature of legal world and the computational reductionism as causes of this gap. In fact, to conduct research in a field composed by two distinct knowledge areas, it is necessary to have a consistent knowledge of both areas in order to produce suitable solutions. If we assume the premise that the use of legal theories decreases the gap between Computing and Law, then the next question is: what particular legal theory should be considered by the ontologist? We defend, in this Ph.D. proposal, that the choice of a legal theory must take into account the needs of the contemporary juridical world. In this sense, the choice of a legal theory that does not take account the importance of principles as legal norms will result in a non-flexible computing solution, distant from the juridical reality. For this reason, we have chosen Alexy’s Theory of Fundamental Rights (Alexy, 2010), (Alexy, 2003) as proposed in (Griffo et al., 2015b). Alexy’s theory of Constitutional Rights or Alexy’s theory of Fundamental Rights addresses some problems of Legal Positivism by proposing the (1) Structure of Constitutional Right Norms and the Griffo, C.. UFO-L: A Core Ontology of Legal Concepts Built from a Legal Relations Perspective. In Doctoral Consortium (DC3K 2015), pages 13-20 13