Educational researchers in Europe are not yet provided with a systematic overview about publicly available research data. As a consequence, an Educational Resources Clearinghouse will be established, providing a platform where educational research data can be collaboratively described. Furthermore, relations between research projects in terms of their applied research methods, concepts and data types can be defined. As a consequence, educational researchers will have the opportunity to classify and compare research design issues like research topics or sample characteristics. The clearinghouse serves as a one-stop-shop for further reference to high-quality educational research data worldwide – information about the resources’ metadata as well as direct linking to educational research data will be provided. The underlying technology of the information gateway is based on Semantic MediaWiki, an extension of MediaWiki. The open source software has been originally developed for the online encyclopaedia Wikipedia and allows the collaborative semantification of links within a wiki [Schaffert et al. 2007]. In practice, domain specific concepts like research project are defined and described on a single wiki page. Properties of this concept, like research topic, data availability or population age are assigned and connected with other concepts in the wiki by annotated linking. This enables semantic searching and browsing along the given properties within the wiki. As a result of the semantic annotations, every wiki page is interpreted as an object of a domain-specific ontology for educational research data. An ontology is an explicit and formal conceptualization of a particular domain of knowledge which expresses relevant concepts and their relations to each other [Brank et al. 2005]. The users of the educational clearinghouse develop this ontology by coming to an agreement about relevant concepts and relations in the wiki – bottom-up and without having to consider a pre-defined ontology. Yet, two aspects must be taken into consideration: (1) users do not realize that they develop an ontology in the wiki and (2) they annotate more data when the wiki is already seeded with some properties and relations [Koussetti et al. 2008]. This can be defined as a bottom-up approach of creating ontologies. Other approaches prefer a top-down methodology from the start, by integrating existing ontologies into the wiki [Vrandečič and Krötzsch 2007]. This is done by automatic ontology import or integrating partial vocabularies.

So far, there exists no ontology about educational research data. To allow collaborative development of such an ontology, an extended bottom-up approach as described in [Koussetti et al. 2008] has been chosen. Numerous international projects from educational research have already been identified, described on a wiki page, annotated with suitable properties and semantically linked to other projects. As of yet, the basic descriptions and property types have been intellectually extracted from existing information on the projects’ websites. The existing ontology now allows users to search or browse educational research data, e.g. identify similar or comparable design methods applied in projects in different countries or with different scopes. In a second step, the ontology provided will be presented to a focus group of educational researchers to possibly redefine and extend the ontology. Finally, the system in use will be evaluated during a given time period, emphasizing on usability and ontology quality.

The project will address the following main research questions: (1) How usable is the semantic wiki technology in the given context? (2) How does the process of developing an ontology with the extended-bottom up approach look like? (3) Which methods are applicable to the assessment of the emerging ontology’s quality? (4) Which strategies for encouraging educational researchers to participate are suitable? Eventually, the semantic wiki may provide a comfortable way to record and retrieve data in the domain. Furthermore, the underlying ontology may serve as reference vocabulary in research projects, e-learning or for other information systems storing educational research data (e.g. databases). The clearinghouse may also accelerate the process of making educational research data publicly available – as it marks a starting point for collecting research data that is there in the first place.