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One of the aims of iCamp is to provide students as well as the academic staff of European Higher Education Institutions with access to distributed content repositories.
By providing interoperability between learning object repositories or – more precisely – all repositories that contain (preferably digital) artefacts relevant for learning, iCamp enables the users of iCamp compatible learning tools to extend their access beyond only locally available material to the variety of learning objects provided in different systems and places. This distributed network of content repositories is based on the Simple Query Interface (SQI, see [1]) and enhances the already existing network built in the context of several European projects, most notably ProLearn, to a level covering an enlarged Europe by including several of the key institutions in the NMS and AC countries, while still improving coverage in the already contributing member states.
SQI is an interoperability infrastructure that enables heterogeneous systems to communicate with each other for the purpose of distributed learning object retrieval. Typically, this communication is based on web services (using SOAP messaging via HTTP as a network protocol). To be put into practice in the joint network of learning object repositories, SQI relies furthermore on a common schema, defining common semantics, and a common data model as well as a format, specifying which common query language is to be used and how results should be encoded and represented (see Figure 1.1, cf. [2]).
Figure 1.1. SQI Layers.
Figure 1.2 gives and overview over the data exchange process between two communicating repositories through their SQI interfaces. Through this abstraction of the data exchange process between different learning systems and tools, the prototype of a networked learning object repository was realised which we are reporting here.
Figure 1.2. SQI Communication Process.
For this prototype network the query language was specified to be keyword bags. As WP4 within the ProLearn Network of Excellence is developing a specification for a joint ProLearn Query Language (PLQL) which has not been finished yet, we intend to reconsider the query language issue to a later point during the project run time. The common schema and accordingly the common results format was specified to be RSS 2.0. In several cases, the SQI targets also support VSQI queries and additional results formats. As soon as the work within ProLearn has been finished we will reconsider the issue of schemata, query languages, and results formats.
The following eight integration cases have been realised up to now: moodle (realised with the AGH instance), Course Online, Drupal (realised with the UPM instance), EducaNext, IVA / Zope, ViPS, OAIster, and .LRN (realised with learn@WU).
In deliverable D3.2, we report the successful prototype implementation for five learning management systems, one learning object repository, one digital library, and – in addition – one content management system. We furthermore successfully developed through these integration cases the base SQI technology for several languages, including PHP, python, xoTcl, C, and Java. We consider the SQI interfaces of the widely used standard soft-ware systems .LRN, Moodle, as well as Drupal, and the interfaces for still considerably wide spread systems as IVA and EducaNext, as being a key achievement enabling the iCamp space to grow beyond the consortium partners.
Additionally and beyond the scope of the network prototype, two building blocks have been investigated, which we consider as important in order to ease access to the network from an end-user perspective and to create the preconditions for deeper integration and enhanced service quality of the network.
This is an SQI mediator that encapsulates the functionality of a federated search module and exposes an SQI provider. This allows other SQI consumers to access all connected repositories by communicating with just one target.
Furthermore, we investigated and prototypically provided an SQI consumer portlet to deliver network services to end-user environments. The portlet is to be deployed especially within institutional Learning Management Systems, but also beyond.
You can get help on how to integrate the portlet on the next subpage. If you want to run your own mediator, you can download the necessary open source software here.
– Stefan Sobernig, Fridolin Wild
[1] Bernd Simon, David Massart, Frans Van Assche, Stefaan Ternier, Erik Duval (2005): Simple Query Interface Specification, PDF, last access: July 24th, 2006
[2] F. van Assche, E. Duval, D. Massart, D. Olmedilla, B. Simon, S. Sobernig, S. Ternier, F. Wild (2006): Spinning Interoperable Applications for Teaching & Learning, In: Journal of Educational Technology & Society, 9(2), IEEE Technical Committee on Learning Technology.
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