Osma Suominen

User-Centric Faceted Search for Semantic Portals

Many semantic portals use faceted browsing, where the facets are based on the underlying indexing ontologies of the content. However, in many cases, like in medical applications, the ontologies may be very large and complex, and do not provide the end-user with intuitive facet hierarchies for conceptualizing the content, for formulating queries, and for classifying the search results. We argue that in such cases end-user facets should be separated from the annotation ontologies, and show how to generalize the semantic view-based search paradigm to take into account this fact. A user-centric card sorting method is proposed for designing intuitive views for the end-users and a method for mapping its facets onto the indexing ontologies and search items is presented. The system has been implemented in a prototype of the semantic portal TerveSuomi.fi, a national health promotion portal in Finland.

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.

Elements of a National SemanticWeb Infrastructure--Case Study Finland on the Semantic Web

This article presents the vision and results of creating the basis for a national semantic Web content infrastructure in Finland in 2003-2007. The main elements of the infrastructure are shared and open metadata schemas, core ontologies, and public ontology services. Several practical applications testing and demonstrating the usefulness of the infrastructure are overviewed in the fields of eculture, ehealth, egovernment, elearning, and ecommerce.

Improving the quality of SKOS vocabularies with skosify

Simple Knowledge Organization System (SKOS) vocabularies are commonly used to represent lightweight conceptual vocabularies such as taxonomies, classifications and thesauri on the Web of Data. We identified 11 criteria for evaluating the validity and quality of SKOS vocabularies. We then analyzed 14 such vocabularies against the identified criteria and found most of them to contain structural errors. Our tool, Skosify, can be used to automatically validate SKOS vocabularies and correct many problems, helping to improve their quality and validity.

Parallel faceted browsing

The widely used paradigm of faceted browsing is limited by the fact that only one query and result set are displayed at a time. This demonstrator introduces an interaction design for parallel faceted browsing that makes it easy for a user to construct and view the results of multiple interrelated queries. The paradigm offers general benefits for a variety of application areas.

Exploring the Linked University Data with Visualization Tools

University data is typically stored in separate data silos even though the data is implicitly richly related together. Such data has a large and diverse user base, including faculty members, students, industrial partners, alumnis, collaborating universities, and media. In this paper, we demonstrate two tools for understanding and using the contents of linked university data. The first tool, Visualization Playground (VISU), supports querying and visualizing the data for example for illustrating emerging trends in universities (e.g., about publications) and for comparing differences. The second tool, Vocabulary Visualizer (V 2), demonstrates the usage of shared vocabularies in the Linked University Data Cloud. It reveals what kinds of data different universities have published, and what terms are used to describe the contents. Such analysis is a basis for facilitating design of Linked Data applications across university data boundaries.

Automatic semantic subject indexing of web documents in highly inflected languages

Structured semantic metadata about unstructured web documents can be created using automatic subject indexing methods, avoiding laborious manual indexing. A succesful automatic subject indexing tool for the web should work with texts in multiple languages and be independent of the domain of discourse of the documents and controlled vocabularies. However, analyzing text written in a highly inflected language requires word form normalization that goes beyond rule-based stemming algorithms. We have tested the state-of-the art automatic indexing tool Maui on Finnish texts using three stemming and lemmatization algorithms and tested it with documents and vocabularies of different domains. Both of the lemmatization algorithms we tested performed significantly better than a rule-based stemmer, and the subject indexing quality was found to be comparable to that of human indexers.

The future of metadata: open, linked, and multilingual – the YSO case

Purpose The purpose of this paper is threefold: to focus on the process of multilingual concept scheme construction and the challenges involved; to addresses concrete challenges faced in the construction process and especially those related to equivalence between terms and concepts; and to briefly outlines the translation strategies developed during the process of concept scheme construction. Design/methodology/approach The analysis is based on experience acquired during the establishment of the Finnish thesaurus and ontology service Finto as well as the trilingual General Finnish Ontology YSO, both of which are being maintained and further developed at the National Library of Finland. Findings Although uniform resource identifiers can be considered language-independent, they do not render concept schemes and their construction free of language-related challenges. The fundamental issue with all the challenges faced is how to maintain consistency and predictability when the nature of language requires each concept to be treated individually. The key to such challenges is to recognise the function of the vocabulary and the needs of its intended users. Social implications Open science increases the transparency of not only research products, but also metadata tools. Gaining a deeper understanding of the challenges involved in their construction is important for a great variety of users – e.g. indexers, vocabulary builders and information seekers. Today, multilingualism is an essential aspect at both the national and international information society level. Originality/value This paper draws on the practical challenges faced in concept scheme construction in a trilingual environment, with a focus on “concept scheme” as a translation and mapping unit.

Renewing the Library System Environment in Finland – What We Have and What We Need

Finnish libraries are in the process of preparing a tender to acquire a new back-end system. The new system is expected provide well operating and deep integration possibilities to existing national infrastructures. Finland has committed on the national level to foster open services, open science, open metadata, and API’s, open source where appropriate, as well as technical and semantic interoperability. This is the set up criteria for the new library system solution. The solution should provide a roadmap for the development of open-linked data.