The ODISSEI Portal allows researchers to find high-quality metadata from the most important Dutch social science data collections. Currently, the Portal includes metadata of the microdata catalogue of Statistics Netherlands (CBS), the LISS panel, the DANS SSH Data Station, the Historical Sample of the Netherlands (HSN) and DataverseNL. An expansion to include metadata from all datasets developed in the ODISSEI Observatory (EVS, GGP, SHARE, ESS, NTR, HSN) is forthcoming. The ODISSEI Portal catalogue is also regularly updated with novel metadata on data collections outside of traditional repositories.
How does the Portal work?
The ODISSEI Portal adds rich variable-level information
Unlike most metadata catalogues which only deal with high-level metadata such as a title or a description of the dataset, the ODISSEI Portal adds rich variable-level information. It creates the highly interlinked and graph-based structures needed to conduct advanced semantic searches. All metadata is stored in a knowledge graph.
The metadata is harmonised through the CESSDA Metadata Model (CMM)
To link across datasets from different providers, several keywords are mapped to Controlled Vocabularies (CVs) such as ELSST (European Social Sciences Language Thesaurus). The CESSDA consortium has translated ELSST keywords into various languages. By linking these enriched keywords to the Portal’s metadata, users can find metadata in both the original language and all its translations.
A pipeline to ingest the machine-readable metadata from external repositories
The Portal ingests machine-readable metadata from external repositories using a pipeline. Each metadata record includes detailed information about its ingestion process. Metadata can also be exported from the Portal in various formats, including JSON and Croissant-ML.
You have found the dataset, what’s next?
The Portal also provides harmonised information about datasets’ access conditions. Through the ODISSEI Data Access Broker (DAB), users can access open datasets and request access to the restricted ones from different providers in one place.
Unclear data licensing and access policies are obstacles in open science, even for open data. The DAB harmonises access conditions and automatically pre-processes them for researchers and providers. This makes the data access request process faster and less time-consuming.
Transfer to analysis environment
Once the data owner reaches an agreement with the user, the ODISSEI Data Access Broker facilitates the owner in making the data available to the user. This is typically achieved by transferring the data to the designated Trusted Research Environment, such as the Secure Analysis Environment (SANE), the ODISSEI Secure Supercomputer (in case of large, complex or sensitive data held at CBS), or the computer of the user (in case of small and/or open data).
