|This page in a nutshell:
Properties, when paired with values, form a statement in Wikidata. 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 are also used in qualifiers.
Properties have their own pages on Wikidata and are connected to items, resulting in a linked data structure.
Properties vs. itemsEdit
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.
|occupation||occupation of a person||profession; job; work; career|
|profession||métier ou occupation d'une personne||métier; occupation|
|zawód||polsko-francuska uczona, fizyk, noblistka||(none yet added)|
However, properties do not have a section on their pages for adding statements or sitelinks. Instead, a property has what is known as a data type.
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.
Other ways to explore properties are covered at parent page: Wikidata:Properties.
Creating a new propertyEdit
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. 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 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.
To request to be a property creator, visit Wikidata:Requests for permissions.
Editing a propertyEdit
Only administrators and property creators have the ability to create properties. However, anyone can edit the label, description, and alias(es) of existing properties.
Just like item labels, labels for properties should be the most common name for the concept represented. However, many properties, such as subclass of (P279) and part of (P361), have specific meanings to, and are constructs of, the Wikidata community (i.e. not pre-existing and widely known objects, people, or events like items are). Moreover, because the labels of many properties may be unknown to users, 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. Aliases of properties are used in the same way as they are for items; all alternative ways of referring to the property should be added.
Descriptions for properties also differ slightly from descriptions for items. While the primary purpose of an item description is to disambiguate the label, a good property description will provide enough information about the scope and context of the property so that users understand appropriate usage of the property without having to consult the property's talk page.
- property: P161
- label: cast member
- description: actor performing live for a camera or audience
- aliases: film starring; actor; actress; starring
The label, description, and alias(es) 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.
Deleting a propertyEdit
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.
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.
Bidirectional relationships and hierarchiesEdit
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.
Frequently used propertiesEdit
Please see Help:Properties/Frequently used properties for guidelines and examples of using properties related to scientific taxonomies, administrative divisions, sources, Wikimedia Commons files, and more.
For related Help pages, see:
- Help:Properties/Frequently used properties, for help with using specific properties
- 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
For additional information and guidance, see:
- Wikidata: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