Comparison and evaluation of ontology visualizations

In the last couple of years a large number of software aiming at visualizing ontologies were introduced, causing difficulties in selecting an objectively suitable visualizing tool. This work lists free and commercial tools in four groups named by the visualizing method used by members of each group. Furthermore a detailed examination of each tool in a separate section is presented. Finally the document comes to an end with an overview of all listed tools and a recommendation of the most powerful ones of each group

OntoPlot: A Novel Visualisation for Non-hierarchical Associations in Large Ontologies

Ontologies are formal representations of concepts and complex relationships among them. They have been widely used to capture comprehensive domain knowledge in areas such as biology and medicine, where large and complex ontologies can contain hundreds of thousands of concepts. Especially due to the large size of ontologies, visualisation is useful for authoring, exploring and understanding their underlying data. Existing ontology visualisation tools generally focus on the hierarchical structure, giving much less emphasis to non-hierarchical associations. In this paper we present OntoPlot, a novel visualisation specifically designed to facilitate the exploration of all concept associations whilst still showing an ontology's large hierarchical structure. This hybrid visualisation combines icicle plots, visual compression techniques and interactivity, improving space-efficiency and reducing visual structural complexity. We conducted a user study with domain experts to evaluate the usability of OntoPlot, comparing it with the de facto ontology editor Prot{\'e}g{\'e}. The results confirm that OntoPlot attains our design goals for association-related tasks and is strongly favoured by domain experts.Comment: Accepted at IEEE InfoVis 201

Visualization of ontology evolution using OntoDiffGraph

Dissertação de mestrado em Ciências da ComputaçãoOntologies evolve with the passing of time due to improvements, corrections or changes in requirements that need to be made. It is hard to keep track of these changes made in an ontology without a tool built specifically for that purpose. The goal of this master’s work is the creation of a visualization technique with the objective of allowing the viewer to easily identify changes made in an ontology by comparing two versions of it. The proposed approach adapts the already existing VOWL (Visual Notation for OWL On tologies) specification so that it can also display the differences between two versions of an ontology through the use of a graph. This was implemented in an application, called On toDiffGraph, however this feature is not all that this application has implemented. In fact, to be able to detect the changes that were made, an algorithm was developed that allows the application to find the axioms that were added or removed in an ontology and display them in a graph. OntoDiffGraph also contains several other features that help with the identification of the changes that were made, such as displaying all axioms of the ontology in a list or filtering nodes and edges of the graph that are not relevant to the visualization of changes made in the ontology. OntoDiffGraph was used in an experiment to obtain user feedback and discover how it performed when compared to a similar application (OWLDiff). The participants gave a lot of important constructive feedback and they also displayed a preference of OntoDiffGraph over the other alternative.As ontologias evoluem com o passar do tempo devido a melhoramentos, correções ou mu danças nos requisitos que necessitam de ser feitas. É difícil observar estas mudanças feitas numa ontologia sem utilizar ferramentas especializadas para este fim. O objetivo deste trabalho de mestrado é a criação de uma técnica de visualização com a intenção de oferecer ao observador a capacidade de fácil identificação das mudanças feitas numa ontologia ao comparar duas versões distintas. A abordagem tomada adapta a especificação VOWL (Visual Notation for OWL Ontologies) de forma a que também seja possível visualizar as diferenças entre duas versões de uma ontologia através do uso de um grafo. Esta abordagem foi implementada numa aplicação, com o nome de OntoDiffGraph, no entanto esta funcionalidade não é tudo o que foi im plementado. Para que seja possível detetar as mudanças que foram feitas, um algoritmo foi desenvolvido que permite que a aplicação, além de identificar os conceitos/relações e propriedades que sofreram mudanças, encontre os axiomas que foram adicionados ou re movidos da ontologia e os apresente num grafo. OntoDiffGraph também tem diversas outras funcionalidades que ajudam na identificação de mudanças, tal como a apresentação de todos os axiomas da ontologia numa lista ou a filtração de nodos e arestas que não são relevantes para a visualização das mudanças feitas na ontologia. OntoDiffGraph foi também utilizado num experimento com o objetivo de obter críticas e comparar o seu desempenho com uma aplicação similar (OWLDiff). Os participantes no experimento ofereceram bastantes críticas construtivas e demonstraram uma preferência por OntoDiffGraph em vez de OWLDiff

Envisioning the Future of Portfolio, Program, and Project Management (P3M): An Ontology

The vision of Portfolio, Program, and Project Management’s (P3M) future has to be visible in all its sagacity, complexity, and granularity to be effective. It has to be visible and meaningful to all stakeholders – to align them, to avoid dysfunctional conflicts among them, and for them to shape the future collaboratively, systematically, and systemically. Such visibility will help: (a) translate the vision into reality without distortion, (b) provide a coherent framework to manage uncertainty and change, (c) create a culture leading to excellence, (d) serve as a constant reference for assessment, feedback and learning throughout the P3M lifecycle, and (e) sustain the viability of P3M. We present an ontology to make the vision of P3M’s future visible. The ontology encapsulates the logic of the vision – its many dimensions, layers of elements, and innumerable components. It is parsimonious and can elucidate the vision’s complexity at different levels of granularity

Semantic Publishing: issues, solutions and new trends in scholarly publishing within the Semantic Web era

This work is concerned with the increasing relationships between two distinct multidisciplinary research fields, Semantic Web technologies and scholarly publishing, that in this context converge into one precise research topic: Semantic Publishing. In the spirit of the original aim of Semantic Publishing, i.e. the improvement of scientific communication by means of semantic technologies, this thesis proposes theories, formalisms and applications for opening up semantic publishing to an effective interaction between scholarly documents (e.g., journal articles) and their related semantic and formal descriptions. In fact, the main aim of this work is to increase the users' comprehension of documents and to allow document enrichment, discovery and linkage to document-related resources and contexts, such as other articles and raw scientific data. In order to achieve these goals, this thesis investigates and proposes solutions for three of the main issues that semantic publishing promises to address, namely: the need of tools for linking document text to a formal representation of its meaning, the lack of complete metadata schemas for describing documents according to the publishing vocabulary, and absence of effective user interfaces for easily acting on semantic publishing models and theories

Actes des 29es Journées Francophones d'Ingénierie des Connaissances, IC 2018

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