Wikidata access methods

Getting data: dereferencing

URI patterns

• P prefixes identify properties
• Q prefixes identify items

Serializations

1. Wikidata's JSON format is not JSON-LD.

Dereference and dig in

curl -LH 'Accept: text/turtle' http://www.wikidata.org/entity/Q6801308

@prefix wikibase: <http://wikiba.se/ontology-beta#> .
@prefix wdata: <https://www.wikidata.org/wiki/Special:EntityData/> .
@prefix schema: <http://schema.org/> .
@prefix cc: <http://creativecommons.org/ns#> .
@prefix wd: <http://www.wikidata.org/entity/> .

wdata:Q6801308 a schema:Dataset ;
  schema:about wd:Q6801308 ;
  cc:license <http://creativecommons.org/publicdomain/zero/1.0/> ;
  schema:softwareVersion "0.1.0" ;
  schema:version "632535452"^^xsd:integer ;
  schema:dateModified "2018-02-17T22:02:36Z"^^xsd:dateTime ;
  wikibase:statements "9"^^xsd:integer ;
  wikibase:identifiers "2"^^xsd:integer ;
  wikibase:sitelinks "2"^^xsd:integer .

Labels and descriptions

curl -LH 'Accept: text/turtle' http://www.wikidata.org/entity/Q6801308

@prefix wikibase: <http://wikiba.se/ontology-beta#> .
@prefix wds: <http://www.wikidata.org/entity/statement/> .
@prefix wd: <http://www.wikidata.org/entity/> .
@prefix wdt: <http://www.wikidata.org/prop/direct/> .
@prefix wdtn: <http://www.wikidata.org/prop/direct-normalized/> .
@prefix p: <http://www.wikidata.org/prop/> .

wd:Q6801308 a wikibase:Item ;
  rdfs:label "McGill University Library"@en ;
  skos:prefLabel "McGill University Library"@en ;
  schema:name "McGill University Library"@en ;
  rdfs:label "Bibliothèque de l'Université McGill"@fr ;
  skos:prefLabel "Bibliothèque de l'Université McGill"@fr ;
  schema:name "Bibliothèque de l'Université McGill"@fr ;
  schema:description "library system of McGill University in Montreal, Quebec, Canada"@en,
    "universiteitsbibliotheek in Montreal, Canada"@nl ;

Truthy values

@prefix wdt: <http://www.wikidata.org/prop/direct/> .

wd:Q6801308 a wikibase:Item ;
  wdt:P17 wd:Q16 ;

• The country (P17) for the McGill library system is Canada (Q16).
• wdt: is the "truthy" value for a given statement; qualifiers such as "start date" or "language of work" are stripped out, and instead appear in separate statements.

Normalized values

@prefix wdt: <http://www.wikidata.org/prop/direct/> .
@prefix wdtn: <http://www.wikidata.org/prop/direct-normalized/> .

wd:Q6801308 a wikibase:Item ;
  wdt:P2581 "01813570n" ;
  wdtn:P2581 <http://babelnet.org/rdf/s01813570n> ;
  wdt:P856 <http://www.mcgill.ca/library/> ;

• wdtn is the "truthy normalized" value for a given statement. The BabelNet ID (0181357n) is also available as a normalized URL.
• The official website (P856) for the McGill library system is at the URL http://mcgill.ca/library/.
• MARC cataloguers rejoice, the 856 lives!

Qualified statements

@prefix wds: <http://www.wikidata.org/entity/statement/> .
@prefix p: <http://www.wikidata.org/prop/> .
@prefix ps: <http://www.wikidata.org/prop/statement/> .
@prefix pq: <http://www.wikidata.org/prop/qualifier/> .

wd:Q48035044 a wikibase:Item ;
  rdfs:label "South End Library"@en ;
  wdt:P856 <http://www.sudburylibraries.ca/en/aboutus/southendlibrary.asp>,
    <http://www.sudburylibraries.ca/fr/aboutus/southendlibrary.asp> ;

wd:Q48035044 p:P856 wds:Q48035044-814e2829-4ba7-ec4b-c397-da81f893b64b .

wds:Q48035044-814e2829-4ba7-ec4b-c397-da81f893b64b a wikibase:Statement,
    wikibase:BestRank ;
  wikibase:rank wikibase:NormalRank ;
  ps:P856 <http://www.sudburylibraries.ca/en/aboutus/southendlibrary.asp> ;
  pq:P407 wd:Q1860 .

Getting data: SPARQL endpoint

Blazegraph

Friendly human interface

• Auto-completion
• Hover for labels
• Results as maps, images, trees, timelines, charts...
• Rich set of examples just a click away

Quirks

• Highly available, averaging over 3M queries/day
• Long-running queries are killed after 60 seconds
• Data is ~5 minutes behind main site
• Wikibase services (extended functions)

Powering live lookups

Label service

SELECT ?library ?libraryLabel WHERE {
  ?library wdt:P31 wd:Q856234.
  ?library rdfs:label ?libraryLabel.
  FILTER(lang(?libraryLabel) = 'en' || lang(?libraryLabel) = 'fr')

SELECT ?library ?libraryLabel WHERE {
  ?library wdt:P31 wd:Q856234.
  SERVICE wikibase:label { bd:serviceParam
    wikibase:language "[AUTO_LANGUAGE],en,fr". }

Geospatial services

• wikibase:around
• wikibase:box

wikibase:box example (libraries between San Jose and Sacramento)

Getting data: Wikibase API

Base URL for all modules: https://wikidata.org/w/api.php

Modules: wbavailablebadges, wbcheckconstraintparameters, wbcheckconstraints, wbcreateclaim, wbcreateredirect, wbeditentity, wbformatvalue, wbgetclaims, wbgetentities, wblinktitles, wbmergeitems, wbparsevalue, wbremoveclaims, wbremovequalifiers, wbremovereferences, wbsearchentities, wbsetaliases, wbsetclaim, wbsetclaimvalue, wbsetdescription, wbsetlabel, wbsetqualifier, wbsetreference, wbsetsitelink, wbsgetsuggestions, webapp-manifest

API: Search entities

• Retrieve entities with labels or aliases that match a string: wbsearchentities
• Query params:

  { "action": "wbsearchentities",
    "format": "json",
    "search": "mcgill university library",
    "languages": "en" }

• Results via API Sandbox

API: Get entities

• Retrieve claims for one or more items: wbgetentities
• Query params:

  { "action": "wbgetentities",
    "format": "json",
    "ids": "Q6801308|Q48035044",
    "languages": "en|fr" }

• Results via API Sandbox ("snak" format)
• claim IDs ("Q6801308$E938C340-3F01-41BA-BF4A-3B19F36337DA") used in wbsetclaim, etc

Best(?) LOD workflow

1. Use wbsearchentities to find matching items
2. Dereference the items with the LOD serialization of your preference

Editing data: QuickStatements

Q849751 → Len → "York University"

• Tab-delimited format for adding/editing Wikidata items (docs)
• Editing a label (Llangcode) replaces the current label, if any.
• Strings are delimited by double quotes

Editing statements

Q849751 → P17 → Q16

Adds a new statement if it does not exactly match the current property

Create an item

CREATE
LAST → Len → "Ajax Public Library"
LAST → P31 → Q28324850

• CREATE creates a new item
• LAST refers to the most recently created item

Add/edit qualified statements

Q41506 → P2196 → 16336 → P585 → +2016-10-23T00:00:00:Z/11

• Add 1 or more P### qualifiers to the statement
• Datetime values use +yyyy-MM-ddThh:mm:ss:Z/precision format

Statements with sources

Q41506 → P2196 → 16336 → P585 → +2016-10-23T00:00:00:Z/11
  → S854 → "https://example.com"
  → S813 → +2018-04-29T00:00:00:Z/11

Use S as the prefix for P### IDs when used as source statements

Applying QuickStatements

• Upload to http://tools.wmflabs.org/quickstatements/ and either:
  • Run in your browser (ongoing feedback but slow for large jobs)
  • Run on the server as a background job

QuickStatements sample

CREATE
LAST	Len	"Ajax Public Library"
LAST	Den	"library system in Ontario, Canada"
LAST	P31	Q28324850	S248	Q52147771	S854	"https://files.ontario.ca/opendata/ontario_public_library_statistics_open_data_2016.csv"	S813	+2018-04-22T00:00:00Z/11
LAST	P17	Q16	S248	Q52147771	S854	"https://files.ontario.ca/opendata/ontario_public_library_statistics_open_data_2016.csv"	S813	+2018-04-22T00:00:00Z/11
LAST	P131	Q386567	S248	Q52147771	S854	"https://files.ontario.ca/opendata/ontario_public_library_statistics_open_data_2016.csv"	S813	+2018-04-22T00:00:00Z/11
LAST	P463	Q7570226	S248	Q52147771	S854	"https://files.ontario.ca/opendata/ontario_public_library_statistics_open_data_2016.csv"	S813	+2018-04-22T00:00:00Z/11
LAST	P969	"55 Harwood Avenue South, Ajax, Ontario, L1S 2H8"	S248	Q52147771	S854	"https://files.ontario.ca/opendata/ontario_public_library_statistics_open_data_2016.csv"	S813	+2018-04-22T00:00:00Z/11
LAST	P856	"http://ajaxlibrary.ca"	S248	Q52147771	S854	"https://files.ontario.ca/opendata/ontario_public_library_statistics_open_data_2016.csv"	S813	+2018-04-22T00:00:00Z/11
LAST	P1174	9457	P585	+2016-00-00T00:00:00Z/9	S248	Q52147771	S854	"https://files.ontario.ca/opendata/ontario_public_library_statistics_open_data_2016.csv"	S813	+2018-04-22T00:00:00Z/11

Load into https://tools.wmflabs.org/quickstatements

Source: https://gitlab.com/denials/wikidata_ontario_public_libraries

Applying QuickStatements

OpenRefine reconciliation

OpenRefine Wikidata extension

In development since August 2017