Wikidata Query Service

Rationale
The Wikimedia Foundation Mobile team is investigating using Wikidata to provide a reading and contribution experience that is better suited to mobile devices.

Contribution
Inspired by the Wikidata game, the team has built WikGrok, a feature that generates simple questions about a Wikipedia article and can send the responses to Wikidata. The ultimate goal of WikiGrok is two-fold:


 * 1) Provide an engaging way for users to add value to Wikimedia projects via a mobile device. WikiGrok contributors will be helping convert the tremendous but unstructured repository of knowledge contained in Wikipedia into structured, machine-readable data in Wikidata.
 * 2) Use the data generated by this feature to provide a better reading and editing experience on existing and new devices/platforms. As Wikidata becomes a more robust repository of structured data about Wikipedia items, we can use it to generate more modular blocks of content to our users across the spectrum of mobile devices (handsets, tablets, wearables), in specialized standalone apps, etc.

Reading
Additionally, on both the mobile site and the Wikipedia native apps, we are experimenting with using Wikidata to enhance the reading experience: using Wikidata short descriptors in search and article titles to help readers get more context at a glance, as well as building infoboxes from Wikidata to provide a better formatted quick fact lookup experience. Eventually, we want these items to be editable directly from Wikipedia, so more readers can become editors and help make Wikipedia better.

However, in order for these projects to scale to production, as well as to provide a benefit to other Wikidata-related projects, we need to build a service that allows for simple and more complex queries of Wikidata items/properties.

Use-cases
We hope to cover a variety of use-cases with WikiGrok, so that it can be a flexible tool for generating new campaigns to meet the changing needs of Wikidata. However, our current hypothesis is that while simple query question types will be easier to generate, the kinds of questions that require more sophisticated queries will be more interesting and engaging for end-users and will be more valuable for populating niche areas in Wikidata.

Simple query
Collect all Wikidata items with a specific claim or property, so that users can add more properties, claims, or references to those items via WikiGrok.


 * Examples
 * all items that are ‘instance of: human’ (claim)
 * all items that have ‘date of publication’ (property)

Complex queries
Collect all Wikidata items that belong to an intersection or combination of parameters (including negation and ranges), so that users can add more properties, claims, or references or references to those items via WikiGrok.


 * Examples
 * all ‘instance of: human’ with ‘birth date: between 1900 and 2000’
 * all ‘instance of: painting’ with ‘creator: Leonardo da Vinci’ and no 'material used' property

Tree traversal
Look for specific data in a tree or collect items from a tree, so that users can add more properties, claims, or references to those items via WikiGrok.


 * Examples
 * Find out what country a city is in by traversing the ‘administrative district’ tree
 * Build a list of all possible occupations by traversing the subclasses and instances of the ‘occupation’ item

Selectively retrieve batches of Wikidata statements about specific items, so that they can be used to create a "quick facts" view on mobile.


 * Examples
 * For all items that are instances of human, retrieve birthdate, death date, occupation, nationality, and family tree