Ontologies
Are Ontologies Involved in Natural Language Processing?
Abraham, Maryvonne (Institut TELECOM, Telecom Bretagne)
For certain disable persons unable to communicate, we present a palliative aid which consists of a virtual pictographic keyboard associated to a text processing from a pictographic scripture. Words and the grammar are given as pictograms. The pictographic lexicon must be organized following the mental lexicon of the user to propose the pictograms of grammar in order to facilitate his (her) task of writing. We discuss the utility of ontologies in the organization of lexicons and in the building of texts.
Special Track on Semantics, Ontologies, and Computational Linguistics
Biskri, Ismail (University of Quebec) | Pascu, Anca (University of Bretagne Occidental) | Dapoigny, Richard (University of Savoie) | LePriol, Florence (University of Paris-Sorbonne)
One of the most salient subfields of AI is computational linguistics, which includes its applied branch - natural language processing (NLP). Computational linguistics is a subfield of AI, developing methods and algorithms for all the aspects of language analysis and their computer implementation. We can see language analysis split into two parts: the theoretic analysis and the applicative one. The theoretic aspect includes standard levels considered in linguistics: semantics, syntax, and morphology. Semantic theories have to be a guide of syntactical theories and morphological developments.
Special Track on Intelligent Tutoring Systems
Ward, Arthur (University of Pittsburgh) | Murray, Chas (Carnegie Learning)
Researchers in the field of intelligent tutoring systems (ITS) seek to create computerized tutors that can rival the learning gains produced by human tutoring, the most effective form of instruction known. The goal of the researchers is to produce ITS that provide flexible, efficient, individualized instruction to every student. Pursuit of this common goal has led them to examine many different aspects of how students learn from tutors, how human tutors interact with their students, and how students learn in collaborative environments. Insights from those studies have informed further research into ways that computer systems can detect and respond to student knowledge gaps, misconceptions, affective states and other attributes. This research has produced important work in student modeling, knowledge representation, dialog systems, and authoring tools for efficiently creating ITS in new domains.
What a Legal CBR Ontology Should Provide
Ashley, Kevin D. (University of Pittsburgh)
This paper discusses the state of the art in CBR ontologies from the perspective of one developing an improved system for case-based legal reasoning. The paper proposes three specific roles for a CBR ontology and illustrates them in the context of the intended output of the new system: a legal classroom discussion of how to decide a case featuring hypothetical reasoning and abstract analogies. The paper distills the ontological requirements for modeling the example’s case-based arguments and assesses whether current research can meet those requirements. The concrete example helps to focus on and define goals for improving CBR ontologies.
Improving Biomedical Document Retrieval by Mining Domain Knowledge
Wang, Shuguang (University of Pittsburgh) | Hauskrecht, Milos (University of Pittsburgh)
When research articles introduce new findings or concepts they typically relate them only to knowledge and domain concepts of immediate relevance. However, many domain concepts relevant for the article and its findings are omitted in the text. This may prevent us from retrieving articles of interest when executing a search query. Approaches such as probabilistic latent semantic indexing (PLSI) overcome this limitation by projecting terms in articles to a lower dimensional latent space and best possible matches in this space are identified. Nevertheless, this approach may not perform well enough if the number of explicit knowledge concepts in the articles is too small compared to the amount of knowledge in the domain. The objective of this paper is to address the problem by exploiting a domain knowledge layer: a rich network of associations among knowledge concepts in the domain of interest. We present a new document retrieval framework that i) extracts associations among knowledge concepts from many documents in the literature corpus; ii) and exploits them to improve the retrieval of relevant documents. We test our approach on the problem of retrieval of biomedical documents and show that it outperforms standard Lucene and BM25 information-retrieval methods.
Spyglass: A System for Ontology Based Document Retrieval and Visualization
Rushing, John (University of Alabama in Huntsville) | Berendes, Todd (University of Alabama in Huntsville) | Lin, Hong (University of Alabama in Huntsville) | Buntain, Cody (University of Alabama in Huntsville) | Graves, Sara (University of Alabama in Huntsville)
This paper describes the Spyglass tool, which is designed to help analysts explore very large collections of unstructured text documents. Spyglass uses a domain ontology to index documents, and provides retrieval and visualization services based on the ontology and the resulting index. The ontology based approach allows analysts to share information and helps to ensure consistency of results. The approach is also scalable and lends itself very well to parallel computation. The Spyglass system is described in detail and indexing and query results using a large set of sample documents are presented.
A Semantic Framework for Uncertainties in Ontologies
Hois, Joana (University of Bremen)
We present a semantically-driven approach to uncertainties within and across ontologies. Ontologies are widely used not only by the Semantic Web but also by artificial systems in general. They represent and structure a domain with respect to its semantics. Uncertainties, however, have been rarely taken into account in ontological representation, even though they are inevitable when applying ontologies in `real world' applications. In this paper, we analyze why uncertainties are necessary for ontologies, how and where uncertainties have to be represented in ontologies, and what their semantics are. In particular, we investigate which ontology constructions need to address uncertainty issues and which ontology constructions should not be affected by uncertainties on the basis of their semantics. As a result, the use of uncertainties is restricted to appropriate cases, which reduces complexity and guides ontology development. We give examples and motivation from the field of spatially-aware systems in indoor environments.
Invited Talks
Aleven, Vincent (Carnegie Mellon University) | Freuder, Eugene C. (University College Cork) | Graesser, Arthur C. (The University of Memphis) | Pustejovsky, James (Brandeis University) | Wiebe, Jan (University of Pittsburgh)
Vincent Aleven Intelligent tutoring systems (ITS) are highly effective in supporting student learning, but are difficult to build. The Cognitive Tutor Authoring Tools (CTAT) project started over 6 years ago with the goals of making it easier for experienced programmers, and possible for non-programmers to create an ITS. CTAT supports tutor building through programming by demonstration, an approach that has been successful in a range of application areas, but that has been applied to only a very limited degree to ITS authoring. Using CTAT, an author creates a tutor by demonstrating correct and incorrect problem solving behaviors, rather than by writing code. The resulting tutors, called exampletracing tutors, evaluate student behavior by flexibly comparing it against the demonstrated problem-solving examples.
Interpretations of the Web of Data
The emerging Web of Data utilizes the web infrastructure to represent and interrelate data. The foundational standards of the Web of Data include the Uniform Resource Identifier (URI) and the Resource Description Framework (RDF). URIs are used to identify resources and RDF is used to relate resources. While RDF has been posited as a logic language designed specifically for knowledge representation and reasoning, it is more generally useful if it can conveniently support other models of computing. In order to realize the Web of Data as a general-purpose medium for storing and processing the world's data, it is necessary to separate RDF from its logic language legacy and frame it simply as a data model. Moreover, there is significant advantage in seeing the Semantic Web as a particular interpretation of the Web of Data that is focused specifically on knowledge representation and reasoning. By doing so, other interpretations of the Web of Data are exposed that realize RDF in different capacities and in support of different computing models.
Mining Meaning from Wikipedia
Medelyan, Olena, Milne, David, Legg, Catherine, Witten, Ian H.
Wikipedia is a goldmine of information; not just for its many readers, but also for the growing community of researchers who recognize it as a resource of exceptional scale and utility. It represents a vast investment of manual effort and judgment: a huge, constantly evolving tapestry of concepts and relations that is being applied to a host of tasks. This article provides a comprehensive description of this work. It focuses on research that extracts and makes use of the concepts, relations, facts and descriptions found in Wikipedia, and organizes the work into four broad categories: applying Wikipedia to natural language processing; using it to facilitate information retrieval and information extraction; and as a resource for ontology building. The article addresses how Wikipedia is being used as is, how it is being improved and adapted, and how it is being combined with other structures to create entirely new resources. We identify the research groups and individuals involved, and how their work has developed in the last few years. We provide a comprehensive list of the open-source software they have produced.