Wikidata

The world's largest public newspaper clippings archive comprises lots of material of great interest particularly for authors and readers in the Wikiverse. ZBW has digitized the material from the first half of the last century, and has put all available metadata under a CC0 license. More so, we are donating that data to Wikidata, by adding or enhancing items and providing ways to access the dossiers (called "folders") and clippings easily from there.

In the EconBiz portal for publications in economics, we have data from different sources. In some of these sources, most notably ZBW's "ECONIS" bibliographical database, authors are disambiguated by identifiers of the Integrated Authority File (GND) - in total more than 470,000. Data stemming from "Research papers in Economics" (RePEc) contains another identifier: RePEc authors can register themselves in the RePEc Author Service (RAS), and claim their papers. This data is used for various rankings of authors and, indirectly, of institutions in economics, which provides a big incentive for authors - about 50,000 have signed into RAS - to keep both their article claims and personal data up-to-date. While GND is well known and linked to many other authorities, RAS had no links to any other researcher identifier system. Thus, until recently, the author identifiers were disconnected, which precludes the possibility to display all publications of an author on a portal page.

To overcome that limitation, colleagues at ZBW have matched a good 3,000 authors with RAS and GND IDs by their publications (see details here). Making that pre-existing mapping maintainable and extensible however would have meant to set up some custom editing interface, would have required storage and operating resources and wouldn't easily have been made publicly accessible. In a previous article, we described the opportunities offered by Wikidata. Now we made use of it.

Wikidata is a large database, which connects all of the roughly 300 Wikipedia projects. Besides interlinking all Wikipedia pages in different languages about a specific item – e.g., a person -, it also connects to more than 1000 different sources of authority information.

The linking is achieved by a „authority control“ class of Wikidata properties. The values of these properties are identifiers, which unambiguously identify the wikidata item in external, web-accessible databases. The property definitions includes an URI pattern (called „formatter URL“). When the identifier value is inserted into the URI pattern, the resulting URI can be used to look up the authoritiy entry. The resulting URI may point to a Linked Data resource - as it is the case with the GND ID property. This, on the one hand, provides a light-weight and robust mechanism to create links in the web of data. On the other hand, these links can be exploited by every application which is driven by one of the authorities to provide additional data: Links to Wikipedia pages in multiple languages, images, life data, nationality and affiliations of the according persons, and much more.

Wikidata item for the Indian Economist Bina Agarwal, visualized via the SQID browser