This document discusses linking educational data as linked open data. It describes several existing educational linked data projects and datasets, including SmartLink, mEducator, and the Linked Education Graph. The Linked Education Graph integrates datasets from various sources into a single RDF dataset with over 6 million resources and 97 million triples. The document outlines challenges in linking educational data and introduces the LinkedUp project which aims to further adoption of linked data in education through an open data competition and infrastructure to integrate and query educational datasets.

1. Linked Data for Education – Datasets & APIs
Stefan Dietze
- Green Hackathon, 14 December, Athens, Greece -

2. TEL data vs Linked Open Data
Linked Data for Education Linked Open Data
Relevant knowledge and data  Vision: well connected graph of open Web data
 Publications: ACM, PubMed, DBLP (L3S), OpenLibrary  W3C standards (RDF, SPARQL) to expose data, URIs
 (Cross-)domain knowledge & resources: BioPortal, historic to interlink datasets
artefacts in Europeana, Geonames, DBpedia, Freebase, …  => vast cloud of interconnected datasets
 Media resource metadata: BBC, Flickr, …  Crossing all sorts of domains
 32 billion triples (September 2011)
Explicit educational data
 University Linked Data: eg The Open University UK,
http://data.open.ac.uk, Southampton University, …
 OER Linked Data: mEducator Linked ER (
http://ckan.net/package/meducator), Open Learn LD
 Schemas: LRMI (http://www.lrmi.net/), mEducator OER
schema (http://purl.org/meducator/ns)
⇒ http://linkededucation.org;
⇒ http://linkeduniversities.org

3. Early work: educational service integration
 SmartLink: Linked Data registry of (educational) datasets / stores and their APIs
 Discovery and lifting of educational data out of heterogeneous repositories
 Transformation of heterogeneous data formats (XML, JSON...) and schemas (eg. IEEE LOM,
Dublin Core) into RDF (pre-requisite for LOD compliancy)
⇒ http://ckan.net/package/smartlink & http://purl.org/smartlink
Data/services integration & retrieval/search APIs
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4. Early work: educational data integration
⇒ http://linkededucation.org/meducator
Data/services integration & retrieval/search APIs Linked Educational Resources
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5. Dereferencable resource URIs
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6. Data so far: SmartLink/mEducator in LOD cloud
 http://ckan.net/package/smartlink
 > 2000 triples so far
 > 300 links to iServe
 APIs (=> wiki) used by several
applications
 http://ckan.net/package/meducator
 > 35000 triples so far
 > 1000 links to DBpedia & Bioportal
ontologies
 APIs (=> see wiki) used by 4 applications
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7. TEL data vs Linked Open Data
Challenges
 Still limited take-up (applications usually focused on small set of datasets)
 Key issues
 Scalability and robustness (distributed data access & retrieval, Big Data integration)
 Data quality (heterogeneous providers, lack of trust)
 Legal and licensing issues
 Lack of benchmarks and evaluation
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8. “LinkedUp” Support Action
Linking Web Data for Education Project – Open Challenge in Web-scale Data Integration
 EC Support Action, kickstarted in November 2012 => http://linkedup-project.eu
Goals
 Push forward adoption of Web data/Linked Data in educational context
 Drive technological advancement of Web data integration technologies
Approach
 Open data competition (initial calls expected early 2013) incl. technical, legal and financial support
 Open data curation !
Partners
+ network of associated institutions (eg BBC, Commonwealth of Learning, Talis UK, …)
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9. LinkedUp data curation
Linked Education Cloud & Linked Education Graph
Educational data gathering - community-approach: Linked Education cloud
 “LinkedUp/Linked Education cloud” as subset of LOD cloud
 CKAN – “The DataHub” (ckan.net, most important data registry) for data collection
(analog to Linked Open Data approach)
 Dedicated group (“linked-education”) for cataloging educational datasets
Educational Data
Educational data integration & infrastructure: Linked Education graph
 Linked Education cloud => Linked Education graph & dataset
 Integration of (selected) datasets into coherent (RDF) dataset
 Infrastructure, unified (SPARQL) endpoint & APIs => http://linkededucation.org
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10. Linked Education graph & dataset(s)
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11. Linked Education graph & dataset(s)
http://data.linkededucation.org/ns/linked-education.rdf
?
<dc:title> <akt:has-title>
OER VideoLecture
Publication
LinkedUniversities http://data.linkededucation.org/.... (details at the end)
educational videos  6 million distinct (but linked) resources
 97 million RDF triples
 21.6 GB of data
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12. Linked Education graph & dataset(s)
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13. Entity enrichment => disambiguation & correlation
Via DBpedia/Freebase
<led:Resource-BBC-519215>
…
<led:title>…gravitating…</led:title>
…
</led:Resource-BBC-519215>
<led:Resource-OpenLearn-2139393292>
…
<led:title>…laws of gravity…</led:title>
…
</led:Resource-OpenLearn-2139393292>
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14. Linked Education graph & dataset(s)
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15. Linked Education graph & dataset(s)
Enabling cross-dataset queries
 Example resource:
=> http://data.linkededucation.org/resource/led/92C8A5E7-7B4D-12A6-F4F2-76A6A8DC7C0A
 Example query (schema alignment & categorisation):
SELECT ?resource ?title WHERE { ?resource led:title ?title FILTER regex(?title,
"linear equations", "i")}
⇒ returns 1102 resources from different datasets: 659 DBLP items, 397 ACM publications, 10
LinkedUniversities educational videos
 Example query (disambiguation & correlation):
SELECT distinct ?entity WHERE {?entity led:hasEnrichmentContext ?dbp_context. ?
dbp_context rdf:type led:EnrichmentContext.
?dbp_context led:hasEnrichment
<http://data.linkededucation.org/ontology/Enrichment/Gravitation>}
⇒ returns 5 resources (LinkedUniversities, mEducator, BBC) enriched with DBpedia concept Gravitation
(even though their descriptions refer to "gravity" or "gravitational" or "laws of gravity").
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16. How to access the data (1/2)
Registries and federated access to data
CKAN – The DataHub
 THE public registry for open Web datasets (almost 5000 distinct datasets)
 CKAN: http://thedatahub.org; LOD group: http://datahub.io/group/lodcloud
Linked Education dataset
 Over 21 GB /6 million educationally relevant resources
 SPARQL endpoint:
http://data.linkededucation.org/openrdf-sesame/repositories/linked-learning
[-selection]?query
 Schema: http://data.linkededucation.org/ns/linked-education.rdf
 Example resource:
http://data.linkededucation.org/resource/led/92C8A5E7-7B4D-12A6-F4F2-76A6A8DC7C0A
SmartLink
 SmartLink dataset: registry of educationally relevant APIs
=> http://ckan.net/package/smartlink, http://purl.org/smartlink
 SPARQL: http://smartlink.open.ac.uk/smartlink/sparql 2012
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17. How to access the data (2/2)
Some individual datasets
ACM Learning Analytics and Knowledge (LAK) Dataset
 Corpus of extracted metadata and full-text from ACM LAK conference series papers
and related publications (expanding)
 Dataset & schema description: http://www.solaresearch.org/resources/lak-dataset/
 LAK Challenge: win fame, an iPad, cash rewards!
 SPARQL endpoint:
http://data.linkededucation.org/openrdf-sesame/repositories/lak-conference?query=%5BQUERY%5D
mEducator Linked Educational Resources
 Over 600 OER (36.000 triples) from different providers
 mEducator dataset: http://ckan.net/package/meducator
 SPARQL: http://meducator.open.ac.uk/resourcesrestapi/rest/meducator/sparql
 Schema: http://purl.org/meducator/ns
 Dedicated search & retrieval APIs available (see http://linkededucation.org/meducator/)
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18. Conclusions and Outlook
Summary, ongoing work & outlook
 Wide range of relevant data sources & APIs available
 Early cataloging (http://linkededucation.org, http://linkeduniversities.org) and
integration/federation (SmartLink, mEducator Linked Educational Resources)
 LinkedUp (http://www.linkedup-project.eu): data curation, assessment and exploitation
 Data cataloging: http://datahub.io/en/group/linked-education for collection of “educationally
relevant” datasets, categorisation and tagging
 Data integration & infrastructure: unified endpoints and APIs at http://data.linkededucation.org
Getting involved
 Submit your own data or tools: LinkedUp Challenge, LAK Challenge, LinkedUp Call for Data
 Participate as LinkedUp evaluation panelist, use case or data contributor & benefit from access to
large network of organisations in Linked Data and TEL
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19. Thank you!
Credits
 Davide Taibi (CNR ITD, Italy)
 Harry Yu & Dong Liu (The Open University, UK)
 Besnik Fetahu (L3S, Germany)
 mEducator and LinkedUp teams
Contact & links
http://purl.org/dietze / dietze@l3s.de
http://linkededucation.org
http://linkedup-project.eu
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