Design of the PORTA EUROPA Portal (PEP) Pilot Project

This talk concerns the conception of an OAI1 compliant service that can manage three different digital historical archives maintained by the European University Institute (EUI) in Florence. This situation requires careful consideration of interoperability issues related to uniform naming, metadata formats, document models and access protocols for the different data sources. In this talk we will present the design approach for the digital archives federation services to be developed in the Porta Europa Portal (PEP) Pilot Project. The PEP pilot project specialised portal should provide high quality information, selected according to the criteria of originality, accuracy, credibility together with the cultural and political pluralism derived from the EUI's profile. The information in Porta Europa will be: relevant, reliable, searchable and retrievable. To test the feasibility and the impact of the PEP project the EUI committed itself to the development of a PEP prototype2 concerning historic topics. To this extent, among the various available digital historical archives three of them were chosen for the implementation of the pilot. Our approach in solving problems of standardization and interoperability in the PEP pilot project is based on two main issues: Metadata standard ( Dublin Core3) Protocols ( OAI-PMH ) The PEP (Porta Europa Portal) project refers to the integration of three digital libraries related to European history topics: Voices on Europe, Virtual Library and Biblio library catalogue. Each of these data source is characterized by: a collection of data objects (books, journals, documents, multimedia objects etc.) available locally or through the network a collection of metadata structures a collection of services (access methods, management functions, logging/statistics, etc.) a domain focus (topic) a community of users Of course the need of integrating the three data sources comes from the topic (European history) and users community which are common to all three archives. Voices on Europe; (http://wwwarc.iue.it/webpub/Welcome.html) Voices on Europe is an archive containing the electronic audio version and electronic transcriptions about a hundred of interviews given by outstanding politician and historians. WWW-VL (Virtual Library) on European History Integration; (http://vlib.iue.it/history/index.html) The Virtual Library (VL) is the Web oldest catalogue, conceived by Tim Berners-Lee. Unlike commercial catalogues, it is run by a loose confederation of volunteers, who compile pages of relevant links for specific areas in which they are expert. The EUI Library Web site contains the complete list of VLs belonging to the WWW VL History Project in the University of Lawrence/Kansas (USA) and mirrored at the European University Institute's Library. Biblio (the EUI historical archives); (http://www.iue.it/LIB/Catalogue/) This is the library catalogue containing more than 250.000 bibliographic records. Access to resources is supported by INNOPAC, well known Library Automation System. The PEP Pilot Project is being developed according to the following steps: Analysis of the three data resources; in this part we first understand the current situation of the resources and we identify the main issues involved in each case. Each resource is characterised by different issues which are elicited and therefore faced. This phase end with a detailed description of the metadata formats, document models and access protocols for each of the data sources. The analysis revealed the strong points and the weakness of each digital library setting the basis for the definition of a common document description model. Definition of the federation architecture (figure 1); the architecture of our federation service4 is structured in three layers: the data source layer where all information is stored with autonomy of representation and access interfaces, the adapter layer were special adapters have to be implemented to provide uniform access and transform the data source specific model into the global model of the federated system, and the federation layer which is responsible for global data integration using an on purpose database and is the OAI data provider and the User interface that will be the OAI service provider. Data Source Layer: these are the archives (digital libraries) whose integration we deal with: Voices on Europe, Virtual Library and Biblio library catalogue. Adapter Layer: this layer provides uniform access to the information, hiding the differences in the data models and query interfaces. Here the metadata are translated from the source specific model into the global model of the federated system. The development of this work is the adoption of the Web services technical framework where a standardized mechanism would be used to describe, locate and communicate with each digital library. The main operation of this layer is the "extraction of data". This operation has to be automatic so that each interface has to be implemented specifically for the resource. As instance SQL queries could be used to extract data from some Data sources (Voices on Europe, Virtual Library) and some external tools such as Innopac tools could be used for the catalogue. Federation Layer and User Interface: in this two layers is implemented the OAI-PMH, in details: Data Provider (The Federation layer) Service Provider (The User Interface) Moreover the Federation layer has to describe Metadata of the three different resources in a common standard to allow in a second step to store them in a unique database. To this extent a common metadata format (Meta Resource Card - MRC) must be devised for the three resources. To effectively address the interoperability issue, the Meta Resource Card should follow the unqualified Dublin Core Standard to define the common fields. In the Federation Layer are implemented interoperability functions, the OAI compliant Data Provider, that is the core of pilot project. The User Interface will be OAI compliant Service Provider and it will use OAI harvesting to extract data. In a first period externally implemented interfaces such as Arc5 could be used as the Service Provider