Christian Mader

Assessing and Improving the Quality of SKOS Vocabularies

Controlled vocabularies are increasingly made available on the Web of Data using the Simple Knowledge Organization System (SKOS) ontology. Assessment of vocabulary quality is important for determining the suitability of vocabularies for reuse in applications and for improving vocabulary development processes. We define 26 quality issues, i.e., computable functions that expose potential quality problems. In an analysis of a representative set of 24 SKOS vocabularies, we found all of them to contain structural errors and/or other quality problems. We propose a set of correction heuristics which we have used to automatically correct a significant proportion of the identified problems. Our reference implementations of these methods, the quality assessment tool qSKOS and the quality improvement tool Skosify, are available for reuse as open-source software.

Finding quality issues in SKOS vocabularies

The Simple Knowledge Organization System (SKOS) is a standard model for controlled vocabularies on the Web. However, SKOS vocabularies often differ in terms of quality, which reduces their applicability across system boundaries. Here we investigate how we can support taxonomists in improving SKOS vocabularies by pointing out quality issues that go beyond the integrity constraints defined in the SKOS specification. We identified potential quantifiable quality issues and formalized them into computable quality checking functions that can find affected resources in a given SKOS vocabulary. We implemented these functions in the qSKOS quality assessment tool, analyzed 15 existing vocabularies, and found possible quality issues in all of them.

Exploring structural differences in thesauri for SKOS-based applications

This paper presents conceptual assumptions about the interaction between the structural specificities of a thesaurus and the quality of a thesaurus-based application output. So far hardly any literature exists that discusses thesaurus modelling requirements with respect to the following thesaurus-specific application areas: classifying, indexing, autocom-plete, query expansion, recommendation and glossaries. By looking at these application areas the authors compare the structural attributes of SKOS and discuss their functional relevance. The authors conclude that taking these assumptions into account can significantly support application-oriented thesaurus modelling hence incrementally improving thesaurus-based applications in terms of modelling scope and effort. An empirical testing of these assumptions is subject to future work.

Quality assurance in collaboratively created web vocabularies

In recent years, controlled vocabularies have become available on the Web using SKOS, i.e. they are linked to each other in order to be used in an interoperable way. Well-crafted controlled vocabularies are beneficial for, e.g., search and retrieval systems that provide functionalities like search term completion, query expansion or the ability for inter-domain queries. Some of these vocabularies are created collaboratively by experts, holding expertise in different domains. In order to support vocabulary contributors to create high quality vocabularies, we propose a method that semi-automatically ensures vocabulary quality in collaborative authoring processes. The proposed approach tackles this issue by (i) defining a set of criteria that serve as a metrics to measure vocabulary quality and (ii) introducing a method to continually assess and improve this quality. As a result of our approach, the developed vocabularies are expected to better fit the intentions of the contributors and are more useful for reuse and adoption on the Web of Data.

Ontology-Driven Unified Governance in Software Engineering: The PoolParty Case Study

Collaborative software engineering environments have transformed the nature of workflows typically undertaken during the design of software artifacts. However, they do not provide the mechanism needed to integrate software requirements and implementation issues for unified governance in the engineering process. In this paper we present an ontology-driven approach that exploits the Design Intent Ontology (DIO) for aligning requirements specification with the issues raised during software development and software maintenance. Our methodology has been applied in an industrial setting for the PoolParty Thesaurus server. We integrate the requirements specified and issues raised by PoolParty customers and developers, and provide a graph search powered, unified governance dashboard implementation over the annotated and integrated datasets. Our evaluation shows an impressive 50% increase in efficiency when searching over datasets semantically annotated with DIO as compared to searching over Confluence and JIRA.

The MEKETREpository - middle kingdom tomb and artwork descriptions on the web

The MEKETREpository (MR) allows scholars to collect and publish artwork descriptions from Egypts Middle Kingdom (MK) period on the Web. Collaboratively developed vocabularies can be used for the semantic classification and annotation of uploaded media. This allows all users with system access to contribute their knowledge about the published artworks. All data, including annotations and vocabularies, are published as Linked Data and can be accessed and reused by others. This paper gives an overview of MRs functionalities and the current state of our work.