Antoine Isaac

Vrije Universiteit Amsterdam | VU · Department of Computer Science

To inform future decisions regarding the use of persistent identifiers (PID) in the common European data space for cultural heritage, we have analysed the usage of PIDs in the metadata that cultural heritage institutions deliver to Europeana. Focusing on the identification of cultural heritage objects and their digital representations, we present s...

Europeana, a digital library that aggregates content from libraries, archives and museums from all around Europe, offers search functionality using the metadata of more than 62 million objects. However, in most cases, this data is only available in one language, while users come from countries with different languages. Europeana’s strategy for the...

Multilinguality is of particular interest for digital libraries in Cultural Heritage (CH), where the language of the data may not match users’ languages. However, multilingual access is rarely implemented beyond the use of multilingual interfaces. We have run an experiment using the Europeana CH digital library as a use case. We evaluate the effect...

Digital cultural heritage resources are widely available on the web through the digital libraries of heritage institutions. To address the difficulties of discoverability in cultural heritage, the common practice is metadata aggregation, where centralized efforts like Europeana facilitate discoverability by collecting the resources’ metadata. We pr...

Digital cultural heritage resources are widely available on the web through the digital libraries of heritage institutions. To address the difficulties of discoverability in cultural heritage, the common practice is metadata aggregation, where centralized efforts like Europeana facilitate discoverability by collecting the resources' metadata. We pr...

In the past years significant research efforts were invested towards the usage of Named Entity recommendation for improving information retrieval in large and heterogeneous data repositories. Such technology is employed nowadays to better understand user’s search intention, to improve search precision and to enhance user experience in web portals....

This article presents an observational study of the virtual graph formed by equivalence links between agent entities across 8 knowledge bases. To evaluate the potential of this linked data graph, we measured the equivalences that it could provide for a real dataset. We crawled the virtual graph by starting from references to agents we found in desc...

The Data Quality Vocabulary (DQV) provides a metadata model for expressing data quality. DQV was developed by the Data on the Web Best Practice (DWBP) working group of the World Wide Web Consortium (W3C) between 2013 and 2017. This paper aims at providing a deeper understanding of DQV. It introduces its key design principles, main components, and t...

In the World Wide Web, a very large number of resources are made available through digital libraries. We (Europeana and data providers) report on case studies that tested the application of some of the most promising Web technologies, exploring several solutions based on the International Image Interoperability Framework (IIIF) and Sitemaps. We als...

Wikidata is an outstanding data source with potential application in many scenarios. Wikidata provides its data openly in RDF. Our study aims to evaluate the usability of Wikidata as a data source for robots operating on the web of data, according to specifications and practices of linked data, the Semantic Web and ontology reasoning. We evaluated...

Online cultural heritage resources are widely available through digital libraries maintained by numerous organizations. In order to improve discoverability in cultural heritage, the typical approach is metadata aggregation, a method where centralized efforts such as Europeana improve the discoverability by collecting resource metadata. The redefini...

Europeana gives access to data from Galleries, Libraries, Archives & Museums across Europe. Semantic and multilingual diversity as well as the variable quality of our metadata make it difficult to create a digital library offering end-user services such as multilingual search. To palliate this, we are building an "Entity Collection", a knowledge gr...

In the World Wide Web, a very large number of resources is made available through digital libraries. The existence of many individual digital libraries, maintained by different organizations, brings challenges to the discoverability, sharing and reuse of the resources. A widely-used approach is metadata aggregation, where centralized efforts like E...

Knowledge graphs represent concepts (e.g., people, places, events) and their semantic relationships. As a data structure, they underpin a digital information system, support users in resource discovery and retrieval, and are useful for navigation and visualization purposes. Within the libaries and humanities domain, knowledge graphs are typically r...

In the World Wide Web, a very large number of resources is made available through digital libraries. The existence of many individual digital libraries, maintained by different organizations, brings challenges to the discoverability and usage of the resources. A widely-used approach is metadata aggregation, where centralized efforts like Europeana...

Drawing upon research and current development work at Europeana, this paper discusses search functionality in the Cultural Heritage sector, focusing in particular on the question of ‘inspiration-oriented’ search, in which users seek out previously-unknown items to serve as creative stimulus. Inspiration-oriented search is identified as a variant of...

Semantic enrichment of metadata is an important and difficult problem for digital heritage efforts such as Europeana. This paper gives motivations and presents the work of a recently completed Task Force that addressed the topic of evaluation of semantic enrichment. We especially report on the design and the results of a comparative evaluation expe...

Cultural heritage institutions are looking at crowdsourcing as a new way and opportunity to improve the overall quality of their data and contribute to a better semantic description and link to the web of data. This is also the case for Europeana, as crowdsourcing under the form of annotations is envisioned and being worked on in several projects....

Drawing upon research and current development work at Europeana, this paper discusses search functionality in the Cultural Heritage sector, focusing in particular on the question of ‘inspiration-oriented’ search, in which users seek out previously-unknown items to serve as creative stimulus. Inspiration-oriented search is identified as a variant of...

This white paper is the product of a joint Digital Public Library of America (DPLA)-Europeana working group organized to develop minimum rights statement metadata standards for organizations that contribute to DPLA and Europeana. This white paper deals specifically with the technical infrastructure of a common namespace (rightsstatements.org) that...

This document is part of the deliverables created by the International Rights Statement Working Group, a joint working group of the Digital Public Library of America (DPLA) and Europeana. It provides the technical requirements for implementation of the Standardized International Rights Statements. These requirements are based on the principles and...

Cultural heritage institutions are looking at crowdsourcing as a new way and opportunity to improve the overall quality of their data and contribute to a better semantic description and link to the web of data. This is also the case for Europeana, as crowdsourcing under the form of annotations is envisioned and being worked on in several projects....

Knowledge organization systems (KOS) can use different types of hierarchical relations: broader generic (BTG), broader partitive (BTP), and broader instantial (BTI). The latest ISO standard on thesauri (ISO 25964) has formalized these relations in a corresponding OWL ontology (De Smedt et al., ISO 25964 part 1: thesauri for information retrieval: R...

This document describes the RDF Application Profile case studies of the "DCMI RDF Application Profiles Task Force" (DCMI RDF-AP) in July 2015. It replaces the use case document from October 2014. The DCMI RDF-AP aims at defining best practices for documenting application profiles, requests for handling RDF application profiles and for RDF constrain...

This report supplements the Report on Use Cases these Use Cases. Requirements are derived from the use cases and specific case studies. See that report for the list of projects that submitted data for this study. The full descriptions of case studies and use cases can be found in the task force wiki. Case studies and the corresponding use cases are...

EDITOR'S SUMMARY Libraries, archives and museums rely on structured schemas and vocabularies to indicate classes in which a resource may belong. In the context of linked data, key organizational components are the RDF data model, element schemas and value vocabularies, with simple ontologies having minimally defined classes and properties in order...

Automatic enrichments can be very beneficial for enabling retrieval across languages and adding context to resources accessible via Europeana. If automatically added enrichments are incorrect or ambiguous, the benefits can be reversed, propagating the errors to several languages and impacting the retrieval performance. Automatic and manual enrichme...

Automatic enrichment of metadata is one option for digital libraries to add multilingual terms to their resources. Adding links to external vocabularies further contextualizes the metadata in a linked data environment. This paper reports on a case study using the digital library Europeana, which implements this type of automatic contextualization a...

The representation of collections in digital library systems that aggregate or exchange cultural heritage data can serve a number of useful functions. In this article, we present specific roles that collections can play in digital aggregations, representational requirements that arise from those roles, and modeling strategies for meeting the requir...

The semantic and multilingual enrichment of metadata in Europeana is a core concern as it improves access to the material, defines relations among objects and enables cross-lingual retrieval of documents. The quality of these enrichments is crucial to ensure that highly curated content from providers gets represented correctly across different lang...

The European Library and Europeana have both an extensive experience in aggregating metadata for bibliographical records or digital resources from the cultural heritage institutions of Europe. For both of them bypassing the challenges offered by multilingual and heterogeneous data is an ongoing effort. The growth of the Semantic Web and the more ge...

Corrigendum to Alan Gilchrist, Marcia Lei Zeng, Stella Dextre Clarke, Antoine Isaac, Patrick Lambe and Judi Vernau (2013) Logic and the Organization of Knowledge - an appreciation of the book of this title by Martin Fricke. A set of short essays. Journal of Information Science, published OnlineFirst on July 1, 2013 as DOI: 10.1177/0165551513480310.

OWL ontology representing the newest ISO standard on thesauri. Description at http://lov.okfn.org/dataset/lov/details/vocabulary_iso-thes.html

The Journal of Information Science does not normally carry book reviews, but when the Editor received a copy of Martin Frické’s book, Logic and the Organization of Information, he thought it was too interesting to ignore. It succinctly encapsulates years of accumulated research and practice in the field, while also adding ‘logic’ into the mix. He a...

With the growing amount and the diversity of aggregation services for cultural heritage, the challenge of data mapping has become crucial.

Europeana is the European Union's flagship digital cultural heritage initiative. the europeana portal, launched in November 2008, showcases the possibility of cross-cultural domain interoperability on a pan-european level. To date, metadata and thumbnails for over 23 million objects have been aggregated from over 1500 providers from the library, ar...

Huge amounts of cultural content have been digitised and are available through digital libraries and aggregators like Europeana.eu. However, it is not easy for a user to have an overall picture of what is available nor to find related objects. We propose a method for hier- archically structuring cultural objects at different similarity levels. We d...

Mapping between different data models in a data aggregation context always presents significant interoperability challenges. In this paper, we describe the challenges faced and solutions developed when mapping the CARARE schema designed for archaeological and architectural monuments and sites to the Europeana Data Model (EDM), a model based on Link...

Simple Knowledge Organization System (SKOS) provides a data model and vocabulary for expressing Knowledge Organization Systems (KOSs) such as thesauri and classi?cation schemes in Semantic Web applications. This paper presents the main components of SKOS and their formal expression in Web Ontology Language (OWL), providing an extensive account of t...

Europeana duomenų modelis (Europeana Data Model – EDM) – tai naujas požiūris į duomenų, kuriuos Europea­na teikia įvairios kultūros paveldo institucijos, struktūravimą ir pateikimą. Šiuo modeliu siekiama didesnės raiškos ir lankstumo, palyginti su dabar taikomu Europeana Semantic Elements (ESE), kurį jis turėtų pakeisti. Esminiai EDM projektiniai p...

In this document we describe the Amsterdam Museum Linked Open Data set. The dataset is a five-star Linked Data representation and comprises the entire collection of the Amsterdam Museum consisting of more than 70,000 object descriptions. Furthermore, the institution's thesaurus and person authority files used in the object metadata are included in...

Europeana is a single access point to millions of books, paintings, films, museum objects and archival records that have been digitized throughout Europe. The data.europeana.eu Linked Open Data pilot dataset contains open metadata on approximately 2.4 million texts, images, videos and sounds gathered by Europeana. All metadata are released under Cr...

The ontology matching (OM) problem is an important barrier to achieve true Semantic Interoperability. Instance-based ontology matching (IBOM) uses the extension of concepts, the instances directly associated with a concept, to determine whether a pair of concepts is related or not. While IBOM has many strengths it requires instances that are associ...

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...

Within the cultural heritage field, proprietary metadata and vocabularies are being transformed into public Linked Data. These efforts have mostly been at the level of large-scale aggregators such as Europeana where the original data is abstracted to a common format and schema. Although this approach ensures a level of consistency and interoperabil...

This paper gives a comprehensive overview over the problem of Semantic Interoperability in the Cultural Heritage domain, with a particular focus on solutions centered around extensional, i.e., instance-based, ontology matching methods. It presents three typical scenarios requiring interoperability, one with homogeneous collections, one with heterog...

Chapitre 04 : Les référentiels : typologie et interopérabilité

The paper for the CHiC pilot lab describes the motivation, tasks, Europeana collections and topics, evaluation measures as well as the submitted and analyzed information retrieval runs. In its first year, CHiC offered three tasks: ad-hoc, which measured retrieval effectiveness according to relevance of the ranked retrieval results (standard 1000 do...

http://www.w3.org/2005/Incubator/lld/XGR-lld-vocabdataset-20111025/

The goal of this chapter is to make the reader familiar with relevant languages that address these two crucial matters: representing conceptual knowledge and querying resource description framework (RDF) data. With respect to conceptual knowledge, there exist very expressive languages such as OWL, which allow formal specification of the ontologies...

Defining roles of agents (i.e., people, organisations, etc.) is required in various Semantic Web applications, including access control, knowledge management and skill repository. So far, many theoretical discussions have taken place on the nature of roles and how to represent them. In this paper, we present how we implemented a lightweight OWL-DL...

We report on ongoing work in Europeana on the conversion of EAD-XML based archival data to an RDF-based representation using the newly developed "Europeana Data Model" (EDM) ontology. This short paper is based on [4].

data.europeana.eu is an ongoing effort of making Europeana metadata available as Linked Open Data on the Web. It allows others to access metadata collected from Europeana data providers via standard Web technologies. The data are represented in the Europeana Data Model (EDM) and the described resources are addressable and dereferencable by their UR...

Documentary approaches: the contents come first The web is designed for public access, a model that does not fit private business, which needs to exercice control and limits over information. Nevertheless, companies can benefit from the web model, with its founding principles of universality, simplicity and technical suppport and the techologies th...

Integrated digital access to multiple collections is a prominent issue for many Cultural Her- itage institutions. The metadata describing diverse collections must be interoperable, which requires aligning the controlled vocabularies that are used to annotate objects in these collec- tions. We demonstrate an interface prototype presenting two collec...

Controlled vocabularies of various kinds (e.g., thesauri, classification schemes) play an integral part in making Cultural Heritage collections accessible. The various institutions participating in the Dutch CATCH programme maintain and make use of a rich and diverse set of vocabularies. This makes it hard to provide a uniform point of access to al...

The Europeana Data Model (EDM) is a new approach towards structuring and representing data delivered to Europeana by the various contributing cultural heritage institutions. The model aims at greater expressivity and flexibility in comparison to the current Europeana Semantic Elements (ESE), which it is destined to replace. The design principles un...

Finding mappings between compatible ontologies is an important and difficult open problem. Instance-based methods for solving this problem have the advantage of fo-cussing on the most active parts of the ontologies and reflect the semantics of the ontologies as they are used in the real world. We evaluate how the feature representation of the insta...

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Ontology matching consists of finding correspondences between ontology entities. OAEI campaigns aim at comparing ontology matching systems on precisely defined test cases. Test cases can use ontologies of different nature (from expressive OWL ontologies to simple directories) and use different modalities, e.g., blind evaluation, open evaluation, co...

In this paper, we report on a technology-transfer eort on using the Semantic Web (SW) technologies, esp. ontology matching, for solving a real-life library problem: book subject indexing. Our purpose is to streamline one library's book description process by suggesting new subjects based on descriptions created by other institutions, even when the...

Most libraries and other cultural heritage institutions use controlled knowledge organisation systems, such as thesauri, to describe their collections. Unfortunately, as most of these institutions use different such systems, unified access to heterogeneous collections is difficult. Things are even worse in an international context when concepts hav...

Semantic search across collections described with heterogeneous metadata is an important problem in the Cultural Heritage field. This paper presents an experiment on enhancing the semantic interoperability of two digital iconographic collections: Mandragore, the iconographic database of the Manuscript Department of the French National Library (BnF)...

Resolving the semantic heterogeneity problem is crucial to allow interoperability between ontology-based systems. Ontology match- ing based on argumentation is an innovative research area that aims at solving this issue, where agents encapsulate difierent matching tech- niques and the distinct mapping results are shared, compared, chosen and agreed...

Thesaurus alignments play an important role in realising efficient access to heterogeneous Cultural Heritage data. Current technology, however, provides only limited value for such access as it fails to bridge the gap between theoretical study and user needs that stem from practical application requirements. In this paper, we explore common real-wo...

Ontology matching consists of finding correspondences between ontology entities. OAEI campaigns aim at comparing ontology matching systems on precisely defined test sets. Test sets can use ontologies of different nature (from expressive OWL ontologies to simple directories) and use different modalities, e.g., blind evaluation, open evaluation, cons...

During the years 2006 and 2007, the BnF has collaborated with the National Library of the Netherlands within the framework of the Dutch project STITCH. This project, through concrete experiments, investigates semantic interoperability, especially in relation to searching. How can we conduct semantic searches across several digital heritage collecti...

Thesaurus alignment plays an important role in realising ef- ficient access to heterogeneous Cultural Heritage data. Current ontology alignment techniques, however, provide only limited value for such ac- cess as they consider little if any requirements from realistic use cases or application scenarios. In this paper, we focus on two real-world sce...

Evaluation of ontology alignments is in practice done in two ways: (1) assessing individual correspondences and (2) comparing the alignment to a reference alignment. However, this type of evaluation does not guarantee that an application which uses the alignment will perform well. In this paper, we contribute to the current ontology alignment eval-...

A technique for converting Library of Congress Subject Headings MARCXML to Simple Knowledge Organization System (SKOS) RDF is described. Strengths of the SKOS vocabulary are highlighted, as well as possible points for extension, and the integration of other semantic web vocabularies such as Dublin Core. An application for making the vocabulary avai...

Purpose To show how semantic web techniques can help address semantic interoperability issues in the broad cultural heritage domain, allowing users an integrated and seamless access to heterogeneous collections. Design/methodology/approach This paper presents the heterogeneity problems to be solved. It introduces semantic web techniques that can h...

State-of-the art mappers articulate several techniques using dierent sources of knowledge in an unified process. An important is- sue of ontology mapping is to find ways of choosing among many tech- niques and their variations, and then combining their results. For this, an innovative and promising option is to use frameworks dealing with arguments...