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A property describes the data value of a statement and can be thought of as a category of data, for example "color" for the data value "blue". Properties, when paired with values, form a statement in Wikidata. Properties are also used in qualifiers.
Wikidata currently has 12,797 properties.
Properties have their own pages on Wikidata and are connected to items, resulting in a linked data structure.
Understanding properties
[edit]Properties are similar to items in a couple of ways. Like items, each property has a label, a description, and even an alias or aliases that can be added in multiple languages. Properties also have statements that help to more completely describe the property, including constraints on how the property can be used.
| Label | Description | Alias |
|---|---|---|
| occupation | occupation of a person | profession; job; work; career |
| profession | métier ou occupation d'une personne | métier; occupation |
| zawód | zawód osoby, zobacz tak?e "dziedzina" | (none yet added) |
However, properties do not have a section on their pages for sitelinks to other Wikimedia projects, and they also do not have external identifiers.
Each property has a data type which defines the kind of values allowed in statements with that property.
Properties aim to relate one type of entity with another type. The type of item a property should be used on is called its domain (Q112036279) and can be enforced using a subject type constraint (Q21503250). If the data type of an item is an Item, than the type of item that should be the value of the property is called is range (Q112036270) and can be enforced using a value-type constraint (Q21510865). If the data type is not an Item, the type of a value a property has can be specified with class of non-item property value (P10726).
Like items, properties also have a unique identifier. While items begin with a Q prefix and are found in the main namespace of Wikidata, properties have a P prefix and are stored in the property namespace.
Finding properties
[edit]Properties can be suggested at respective classes using properties for this type (P1963). E.g. organization (Q43229) will list all properties relevant to any organization.
See Statistics for additional summaries of existing properties.
Search
[edit]Several external tools exist to list properties, for instance:
Lists
[edit]- Special:AllPages/Property: (List by alphabetically sorted number)
- Special:ListProperties + Get a list of properties by data type
- Wikidata:List of properties
- Wikidata:Database reports/List of properties/Top100
- Wikidata:Database reports/List of properties/all
- Template:Property lists
Creating properties
[edit]Before a new property is created, it has to be discussed and documented at Wikidata:Property proposal first. When after some time there are some supporters, but no or very few opponents, the property is created by a property creator or an administrator (see List of property creators). After creation, relevant documentation is moved to the corresponding property's talk page, where usage of the property is further discussed.
When proposing properties, keep in mind that each property should be expected to be used by at least 100 items; if a proposed property cannot be used this many times, it likely should not be added to Wikidata (of course, there are exceptions to this rule).
To propose a property, click here and choose a topic category. Click the blue button "Create request page" and then fill out the provided template with as much information as possible. Make sure to include a possible property name in English (this will be the label), a description, the data type, examples of the type of item that may bear the property, and an example of how the property would be used. Don't worry about getting everything right the first time; that's what the discussion process is for.
If you are interested in being involved at the property proposal level for a specific subject matter, consider joining or creating a WikiProject, a group of contributors who want to work together to improve a particular aspect of Wikidata. These groups often focus on how to best represent the data for a particular area of knowledge.
For more information on the property creator role, see Wikidata:Property creators#Requesting this right. To request the userright, visit Wikidata:Requests for permissions/Other rights#Property creator.
Editing properties
[edit] | Warning: You need to be confirmed or autoconfirmed to edit properties. |
Property entities can be edited like item entities with labels, descriptions, aliases, and statements.
Property labels should be as unambiguous as possible so that it is clear to a user which property is the correct one to use when editing items and adding statements. Properties rarely refer to commonly known concepts but they are more constructs of the Wikidata with specific meanings. Unlike items, property labels must be unique.
Property descriptions are less relevant for disambiguation but they should provide enough information about the scope and context of the property so that users understand appropriate usage of the property without having to consult additional help.
Property aliases should include all alternative ways of referring to the property.
Example:
- property: P161
- label: cast member
- description: actor performing live for a camera or audience
- aliases: film starring; actor; actress; starring
Label, description, and aliases of a property are first discussed by the community during the property proposal process. Major changes to a property should be discussed on its talk page first.
See Help:Data_type#Changing_datatype for changing the datatype of a property.
Deleting properties
[edit]If you think a property should be removed from Wikidata (for example, if is a duplicate of another property in use), you will have to make a request for its deletion. To do so, follow the steps listed at Wikidata:Properties for deletion.
Using properties
[edit]Wikidata relies on consistency. For instance, all persons should have common properties whenever possible, whether they are politicians, artists or scientists, living or historical, fictional or not. If you are unsure whether the property you are using is most appropriate for the statement, consult the property's discussion page or ask on Wikidata:Project chat. An automatically generated list of properties currently supported by Wikidata can be found at here. Community-maintained lists can also be found at Wikidata:List of properties.
Property constraints
[edit]See Help:Property constraints portal.
Bidirectional relationships and hierarchies
[edit]Wikidata does not support automatic bidirectional links (phabricator:T51165), so some properties need to be added and maintained twice. If, for example, A is a child of B on A's item page, the relation B as the parent of A also needs to be maintained on B's item page.
In general, only simple hierarchical properties should be recorded as statements. For example, record properties like child (P40)–father (P22) and/or mother (P25), but not properties like grandchild–grandparent, niece–aunt, niece–uncle, etc. Such additional relationships can be derived from the existing data.
Property misuse
[edit]Every Wikidata property is intended for a specific purpose. When a Wikidata property is used in a way that goes against the consensus of how the property is meant to be used, we speak of property misuse. Wikidata attempts to combat property misuse with property constraints and entity schemas. If a property is misused because there doesn't exist any good alternative property, a new property may be proposed.
Frequently used properties
[edit]Please see Help:Frequently used properties for guidelines and examples of using properties related to scientific taxonomies, administrative divisions, sources, Wikimedia Commons files, and more.
See also
[edit]For related Help pages, see:
- Help:Frequently used properties, for help with using specific properties
- Help:Basic membership properties, detailed explanation of three important properties: instance of (P31), subclass of (P279) and part of (P361)
- Wikidata:List of properties, community-maintained lists of Wikidata properties - Special:AllPages/Property:, a special page showing all properties
- Help:Statements, which explains what statements are and what rules they follow
- Help:Qualifiers, which explains what qualifiers are and what rules they follow
- Help:Items, which explains what items are and what rules they follow
- Wikidata:Property proposal, to discuss new properties before they are created - Wikidata:Properties for deletion to nominate properties for deletion
- Wikidata:Property creators, for users granted the technical ability to create properties
- Wikidata:WikiProjects, a list of users who work together to improve representation and coverage of a specific topic or domain
- Wikidata:Relation between properties in RDF and in Wikidata
- Wikidata:WikiProject Ontology
- Wikidata:Identifiers for identifiers in Wikidata in general and identifier properties in particular
- Wikidata:WikiProject Properties
- MediaWiki:Wikibase-SortedProperties controls the order in which properties are presented on an item
For additional information and guidance, see:
- Project chat, for discussing all and any aspects of Wikidata
- Wikidata:Glossary, the glossary of terms used in this and other Help pages
- Help:FAQ, frequently asked questions asked and answered by the Wikidata community
- Help:Contents, the Help portal featuring all the documentation available for Wikidata