Commons:Depiction guidelines/gu
|
The proposal may still be in development, under discussion, or in the process of gathering consensus for adoption. References or links to this page should not describe it as "policy".
|
|
This proposed guideline is disputed; see Commons:Depicts. |
The Wikidata depicts (P180) property is widely used on Wikidata to describe the content of certain items. It is also available on Wikimedia Commons to give structure to media descriptions, as part of the Structured Data on Commons project. Depicts statements are used to describe more than 12 million files on Commons (May 2023).
== The importance of depicts==
Language and translation
Prior to the introduction of structured data, file information and categories on Commons could only be added in a single language, which was most commonly English. The Wikidata depicts (P180) property, however, can be described in multiple languages. Adding depicts statements to media files therefore transforms Wikimedia Commons into a truly multilingual platform, where readers of any language can find, understand, and use media files.
Searchability, findability, and reuse
Depicts statements are used by MediaSearch to find the most relevant results.
At first, MediaSearch runs queries that include statements and captions that use Structured Data. Next, it expands and searches terms based on Wikidata labels (the most common name that a Wikidata item would be known by). Lastly, it can further expand based on Commons categories and text-based information. This means that, in addition to full-text matching, MediaSearch includes results that have a depicts statement of any Wikidata entity that matches a user's search term. Similarly, it includes results that have a relevant digital representation of (P6243) statement.
By taking advantage of statements like depicts, MediaSearch works in any language supported by MediaWiki and does not require knowledge of English. MediaSearch also powers the visual editor on Wikipedia, allowing more image results, in more languages, to show up to illustrate Wikipedia articles.
Furthermore, depicts statements are used by tools that help users find relevant images for unillustrated Wikipedia articles, a new feature in development. You can learn more about image suggestions here.
== Recommended best practices==
Depicts level of detail
General recommendations
The primary purpose of depicts (P180) statements on Commons is to identify, in a structured way, the items clearly visible in a media file.
Wikidata has entities at varying levels of detail and along different ontological dimensions. MediaSearch cannot always reliably infer relationships between them. Therefore, to optimize a media file for discovery, multiple depicts (P180) statements should be added, both general and specific, taking into account different ontological dimensions.
For example, this image of the fictional dog Lassie should have the statements dog (Q144) (class of organisms), Rough Collie (Q38650) (dog breed), Lassie (Q941640) (fictional character), and Pal (Q7126106) (the individual dog depicted).
Another example is this image of a Sequoia tree, which should have both Sequoia (Q1975652) (a taxon) and tree (Q10884) (a woody plant) depicts statements. Even though, in everyday speech, the term "Sequoia" may often refer to a "Sequoia tree" (as opposed to Sequoia seeds or Sequoia wood, etc.), in the Wikidata ontology Sequoia is considered a subclass of taxon (Q16521). For that reason, the tree (Q10884) should be added to allow for more precise searches.
As a consequence, it is recommended to add multiple depicts statements, both general and specific, taking into account different ontological dimensions. Note, however, that redundant tagging along the same ontological dimension should be avoided wherever possible. For example, if an image shows a dog, there is no need to add the entire taxon tree of Canis familiaris (Q20717272): Canis (Q149892) , Canidae (Q25324), Caniformia (Q27414), Carnivora (Q25306), etc. However, in practice, it may well happen that one user applies a more general depicts statement, and another user comes along at a later point in time and is able to apply a more specific one. In this case, the more specific depicts statement should always be added. If the two statements are undisputably on the same ontological dimension (like for example body of water (Q15324) and lake (Q23397)), the less specific statement can be removed. If in doubt, it is preferable to keep both statements. There is no need for the community to try to root out all redundant statements. The tools making use of the data are able to take care of this.
If there are multiple items clearly and deliberately depicted in the media file, all should be added as separate depicts statements, within reason. The most significant ones should be marked as "prominent" (see example below). For files that depict dozens or hundreds of items (e.g., movies) only those items which are most prominent should be listed.
If groups of the multiple depicted items are a common grouping, and have a grouped item on Wikidata, the grouped item should also be added as a depicts statement. For example File:Bonnieclyde_f.jpg should have the statement depicts: Bonnie and Clyde (Q219937) as well as depicts: Bonnie Parker (Q2319886) and depicts: Clyde Barrow (Q3320282).
What items not to add
Parts of a bigger item: The depiction of a face (Q37017) usually implies the presence of a nose (Q7363), nostril (Q858590), and nasal hair (Q1899093). It is not necessary to list them all on every portrait. Instead just state that the portrait depicts the person in the portrait. Anatomical or other compositional relationships can already be modelled within Wikidata.
Abstract concepts and value judgments: Depicts statements should include what is visible in the image. The photo of the sequoia tree may be beautiful, and trees may be related to the abstract idea of nature, but do not add beauty (Q7242) or nature (Q7860). Lassie is known as a smart dog, but the photo does not depict intelligence (Q83500).
Items expected to be covered by other statements: Many media include incidental items, actions, locations, context, formatting choices, or background, that are not the primary items depicted. As structured data on Commons expands, we expect to have additional properties enabled where these extra items can be specified. In the meantime, it is best to refrain from specifying these as depicts, unless they are central to the purpose of the media.
For example, some expected properties include:
- location
- depicted in background
- clothing
- format (e.g. monochrome photography, daguerreotype, oil painting, portrait)
- season/date/time
- photographer or artist
- genre (e.g. modern art)
Comparison to Categories
It is important to understand that Structured Data on Commons does not function like the Commons category system. Most notably, it tends to avoid creating specific items for intersections of concepts that are on different ontological dimensions. Thus, while Commons has a category Sequoia sempervirens (foliage), depicts statements would refer to two different Wikidata items: Sequoia sempervirens (Q150129) (the taxon), and foliage (Q18250160) (part of a plant). To what extent the two should be connected by a qualifier to allow for more precise statements is still up for discussion.
As the structured data in search and the functionality of the search engine are still very incomplete and not even near the usability of the category system, it is recommended to continue to apply categories to images. The general rule for categories is to always place an image in the most specific categories, and not in the levels above those. See:
Commons:Categories#Over-categorization.
Mark depicted items as prominent
In a depicts (P180) statement, it is possible to identify the main features of an image using the ‘mark as prominent’ option. This is particularly important if many depicts statements have been added to a file.
Multiple depicts statements make it hard to know which statements are the most important or relevant ones in a file. Statements essentially only have two states: something is in the file, or it is not. There is no further detail about just how relevant something is in that file.
To choose which depicts statement to 'mark as prominent', you should ask yourself:
Are the depicts statements equally important, or is one of them the obvious subject and the other a less relevant background detail? If so, which one is more prominent?
Is a depicts statement on one file more prominent than the same depicts statement on another?
The Sessão do Conselho de Estado (Q43485263) painting is a good example of the use of ‘mark as prominent’. There are several characters depicted in the work, most of them on the same disposition, but the main subject and focus is the female character, Maria Leopoldina of Austria (Q84239), who is also represented in a different color.
As a feature, ‘mark as prominent’ enhances the accessibility of media files for people with visual disabilities, as it is a structured way to differentiate between elements displayed in an image, especially considering that not all media files on Wikimedia Commons have a Wikidata item (or are notable enough to have one) to be described in a structured and multilingual way on that platform. When querying the structured data, 'prominent' statements can be found by searching for statements with rank "preferred".
Make sure you have selected the right Wikidata item
Wikidata is a very large database and includes many items with identical names. These items should have descriptions to guide you to the correct choice. For example, when adding a depicts statement for this photo of a banana, you may be tempted to enter "bananas". The first search result is not banana (Q503) but Bananas (Q806092), the 1971 film by Woody Allen. Wikidata items are typically singular, and typically case sensitive such that if you are looking for a fruit but the item is capitalized, it is likely incorrect. If you are unsure, just click on the item to make sure it is what you are looking for.
Good practices and advanced modelling examples
Several good practices and examples may be found on the Modeling Depiction page, in particular for the specific case of Works of Art.