1. Cross-linking and Referencing Data and Publications in CLADDIER Brian Matthews, E-Science Centre, STFC Rutherford Appleton Laboratory

2. About CLADDIER Bryan Lawrence (PI, BADC) Sam Pepler (Project Manager, BADC) Sue Latham (BADC) Pauline Simpson (NOCS) Jessie Hey (Southampton) Brian Matthews (STFC) Catherine Jones (STFC) Alistair Miles (STFC) Katie Portwin (STFC) Shoaib Sufi (STFC) Kevin O’Neil (STFC) Katherine Bouton (Reading, NCAS) Citation, Location and Deposition in Discipline and Institutional Repositories Funded via a JISC grant, through the Digital Repositories programme - July 2005-Oct 2007

4. Citation and linking in repositories In order to achieve this scenario we need to provide a set of key mechanisms Publishing of Data –Conventions for the citation of data –Can then treat data citation in similar way to publications Browsing and searching –across different repositories –across data and publication Cross-citation of data and publication –forward and backward citation –need to maintain currency of citation links –A simple mechanism to push citation information between repositories A practical look at citation of data and how repositories could communicate citation information.

5. Data Publication In this context “publication” is defined as the process through which data is fixed and made retrievable over the long term, and may imply that there has been some quality control process. –Defining data : fixing and encapsulating a “meaningful” data set –Quality Control : Publishers, Data Centres Natural Environment Research Council, Mesosphere-Stratosphere- Troposphere Radar Facility [Thomas, L.; Vaughan, G.]. Mesosphere- Stratosphere-Troposphere Radar Facility at Aberystwyth, [Internet]. Version 2, Cartesian products. British Atmospheric Data Centre (BADC), 1990- [cited 2006 Apr 25]. Available from http://badc.nerc.ac.uk/data/mst.

6. Browsing and Searching Browsing and searching across different repositories across data and publication CLADDIER has provided a harvesting and search tool to support cross- repository searching

7. Discovery Service The Discovery Service gives a broad-brush search Give you both publications and data sets indexed by keyword Google across repositories. Uses OAI-PMH – a conventional approach Simple – but it works! Simple key-word searching Three participating repositories in the pilot: BADC, STFC ePubs, SOTON ePrints

8. Adding Cross-Citations Traditional Citation Cross Citation Cannot tell whether the data and publication are actually related. –what data and publications inspire a piece of work (generating a new data set) –what publications arise from a data set We need to exploit the concept of cross-citation to see whether items are actually related.

9. Maintaining Links Ideally the archives holding the datasets and publications would be notified that a paper citing them had been submitted. –Metadata associated with those records would be updated to reflect the citations. –The metadata in the publication repository should also link to the metadata in the data archives and vice versa. –It would be great if this notification could be done automatically. Tedious to enter citations “forward citations” (“cited-by”) are hard to track We adapted a protocol from the world of Blogging –Trackback –Designed to allow cross-referencing of blog articles –Extended to allow richer metadata

10. Trackback Protocol

11. Sender Publication This publication has a citation to a technical report

12. Adds Citation Sends trackback call to this URI

13. Embedded Metadata Trackback URI Formats accepted

14. After Trackback – cited-by link added Receiver Publication Added this cited by link

15. Notes on Trackback A simple existing protocol –P2P – loosely federates repositories –Extended to carry metadata of the citation –To add “cited-by” links Can also indicate which metadata is expected –Simple Dublin Core –ePrints Application Profile Can also use the metadata of the receiver –Improves the citation metadata Implemented in ePubs –Also partially in BADC –Receiver only – send email to admin. Some problems or extensions are under consideration Link to metadata– not full text Spamming – anyone could send trackbacks –Whitelists –Administrator intervention Multiple entries –Same citation multiple times –Same citation in different repositories Retraction of citation –A delete protocol

16. Conclusions CLADDIER supports the scientific process with federated repositories This requires the cross-linking network of information objects. Which needs to be stored, maintained and searched Now doing some user testing Tools and ideas relatively straightforward Lots of gluing of existing components Keep it simple – so it will get used http://claddier.badc.ac.uk/