Digital curation of cultural heritage collections published as Linked Open Data: proposal for an authorial model

Context: Cultural Heritage objects have been represented and published on the Web as digital objects using Linked Open Data - LOD technologies. These collections have high cultural value because they result from curation processes carried out by institutions such as archives, libraries and museums; many of them have thematic intersections or are related to other resources also available on the web. Although published as LOD, these collections remain as "information silos", isolated from each other, not integrated. For such initiatives to reach their maximum cultural and educational potential, the digital objects in these collections should be integrated, interrelated with each other and with other entities represented as digital resources, such as authors, artists, historical personalities, themes, events, dates or historical and artistic periods, and places. This integration, that is, relating digital objects to each other and to other resources, classifying them by their typology, commenting on them, etc, is not given "a priori", it is the result of curation "a posteriori" to the publication of these collections as LOD. These digital curation works must become authorial, permanent and reusable resources, in the form of exhibitions, classes or annotated virtual collections.

Problem: How to integrate digital objects from these collections with each other and with other resources using LOD technologies, forming new curated, authorial, permanent informational resources with greater cultural value, such as exhibitions, classes, museums or virtual libraries, about these Cultural Heritage objects themselves, about themes, characters or cultural or historical events related to them?

Objectives: Develop a model - MIC, Integrated Curatorial Model - for curatorial activities on digital cultural heritage objects - DHO – collections published over the Web as LOD by different institutions that integrates such collections into permanent, authorial and reusable resources, the Curatorial Work; MIC's Curatorial Work intend to mimic an exhibition catalog where a curator proposes a new look at that set of objects, contextualizes them, reveals new relationships, often unusual, between them, and proposes a narrative about such objects; implement MIC using LOD and named graph technologies.

Methodology: This is ongoing research. The steps to develop the MIC were the following: identification of user's requirements, curator and users' tasks, bibliographic and documentary research, identification and analysis of related vocabularies/ontologies for possible reuse, conceptual modeling, implementation using LOD and named graph technologies.

Results: The curator's tasks, which guided the development of the MIC, are the following: C1 – Select the appropriate DHO that will integrate a digital curation work - CW. C2 – Sort these DHOs in a meaningful way (by their IRIs). C3 – Create, save and identify through a persistent access "link", a CW, making them independent and permanent web resources. C4 - Relate two DHOs in a meaningful way using, when appropriate, the CRR Vocabulary. C5 - Relate OPD with Agents - authors, artists, historical characters -, Themes, Cultural Events (concerts, ballets, exhibitions) or historical events, Events or Historical Periods, Places, or other resources, in a meaningful way, using, when appropriate, the CRR vocabulary. C6 - Sort/Organize DHOs by types. C7 - Justify any relationship or Classification/Organization created through text and/or citation. C8 - Date (assign a date) any culturally relevant relationship or Classification/Organization made by him. The MIC user's tasks are as follows: U1- Allow users to recover digital objects. U2 - Allow users to retrieve DHO Culturally Related to a given digital object. U3 - Allow users to recover DHO that belongs to the collection of a heritage institution. U4 - Allow users to retrieve narratives - CW - from a specific curator. U5 - Allow users to retrieve narratives - CW - on a topic. U6 - Allow users accessing an DHO, to retrieve narratives in which it is mentioned. U7 - Allow users to retrieve narratives. U8 - Allow third parties to comment on both the CW as a whole and specific Culturally Relevant Relationships or Classifications/Organizations established by a digital Curator within a CW.

It is important to note that neither the MIC nor a digital curator has any control over the standardization or format of any web resource that may be used in a CW. Heritage data published as LOD are heterogeneous as they describe different types of objects and the conceptual models or standards used may vary by institution.

The MIC class diagram includes external entities – general categories of web resources that form context such as Agents, Concepts/Themes, Time and Space, which may have culturally relevant relationships with DHO from collections published as LOD. The core of the model includes the entities E21 Curators, E22 Publishers, E08 Curatorial_work, the most important, E080 Sequence, the sequence of resources chosen by the Digital Curator to compose his E08 Curatorial_work, and E 081 CRR-annotation. E080 Sequence is a list, ordered or not, of IRIs of culturally relevant relationships between heritage web resources that the Digital Curator considers appropriate to present his point of view, developing his narrative, his E08 Curatorial-work. An E08 Curatorial_work is composed of one or more E081 CRR_annotation, the annotation/comment made by the Digital Curator of a relationship between two web resources chosen to make up the E08 Curatorial_work. E082 Document is a citation with a link to a digital document that supports the specific relationship made by the Digital Curator. E09 Comments are third-party comments made about a E08 Curatorial_work. E01 Digital_Heritage_objects are digital objects originating from collections of Heritage institutions and published on the web as LOD. R01 CRR_rel-Types are the different types of relationships between E01 Digital_Heritage_objects, among themselves and with external entities, systematized in the CRR Vocabulary.

Conclusions: An implementation of the MIC using LOD technologies and named graphs is presented, covering digital objects interrelated with each other and with other Web resources, comments, digital bibliographic references with texts complementary to the description of the object and as justification for the comments made by the curator. It is expected that the model will serve as a basis for the development of authorial tools for digital curation, or browsers through which users can browse DHOs, and curatorial works that integrate, annotate and comment on them.