Together with my colleague Matthias Palmér I participated in the “Hack4Europe!” competition in Stockholm which has been arranged by the Swedish National Heritage Board in the context of the Europeana project. The goal of the competition was to show the potentials of the Europeana content and APIs by building applications to showcase the social and business value of open cultural data.
Hannes Ebner and Matthias Palmér at Hack4Europe! in Stockholm. (BY-NC-SA by Kristina Alexanderson)
During the hack day we worked in a team of two (representing our newly founded spin-off MetaSolutions) and developed a showcase to demonstrate how heterogeneous metadata can be managed using an approach that we have developed in research projects both at the Royal Institute of Technology and Uppsala University. During Hack4Europe! a combination of the SCAM framework (EntryStore) and Confolio (EntryScape) is used, and both applications are extended so that they can search in Europeana and extract Europeana metadata from the search results. This allows for adding resources directly from a Europeana search result to a user’s personal portfolio for further annotation with educational metadata (or, depending on the use case, some other metadata in a non-educational context).
Screenshot of the demonstrated Europeana showcase.
The demonstrated use case was to search for resources which are suitable to be used in an educational context and to turn them into learning resources by annotating them with educational metadata. Technically this means searching and caching metadata described using the Europeana Data Model and adding educational metadata (e.g. in LOM/DCAM) on top of it. Everything is integrated into the Confolio interface and the end user does not have to know anything about where the metadata originates from, which standards are used, etc.
See the following video for a demonstration of our use case at the end of the competition:
The annotation process of Europeana content with educational metadata as implemented in our showcase is greatly supported by the Resource and Metadata Management Model (ReM3) which is described in a paper submitted to the Semantic Web Journal (not yet accepted). ReM3 is an information model for keeping track of resources and their metadata. It is based on the concepts of Contexts and Entries where each context manages a set of entries. An entry contains a resource, descriptive metadata about the resource and some administrative information about the entry.
Schematic overview of an ReM3 entry
The information model is RDF-oriented and relies on the concept of Named Graphs (NG). This is used to express that NGs are related, as it is the
case when the same resource is described in different contexts. In a typical situation where already existing metadata is built upon – such as in our Europeana showcase – the referenced resource is described by an additional metadata graph, resulting in at least two metadata graphs per resource: the original one from Europeana and the additional one with educational metadata in our system.
The relation between the original external metadata and the newly created metadata is stored in the entry information, where it is indicated that there are multiple descriptions for the same resource. The use of NGs makes contextualisation of metadata possible. Without the fourth piece of information in the quadruple it would be hard to differentiate between triples from different sources.
The information structure of ReM3 is represented by a hierarchical URI model which has been implemented as a REST-ful interface using HTTP. An easy-to-use and REST interface which exposes the functionality of ReM3 allows for enrichment of metadata as the protocol makes communication in both ways possible (read/write). Resources in other systems can be described by linking to them and building a connection between the metadata and the resource. Such connections are in turn exposed using Linked Data which integrates heterogeneous information sources.