Watchlists

Fundamental to the reliability of Wikipedia content is that pages are watched by long-term Wikipedians, either through watchlists or Recent changes patrol, and that it is easy to revert bad edits. As a result, vandalism can be dealt with swiftly. For troublesome content, Wikipedia can apply a degree of page protection to articles.

In contrast, a media file on Commons generally has one person watching it: the primary and usually sole author. Other users may edit the file description page to add and remove categories, add other language descriptions, tag the image as being of good quality, etc., but usually those editors do not care to watch the file afterwards. They may in fact be applying those changes with a bulk-edit tool or through a bot.

When a file is changed on Commons, a new version replaces the old one. Immediately all Wikipedias referencing this file will start displaying the new version. This change will not appear on the watchlists of anyone on Wikipedia. For static images, the change may be immediately noticeable to anyone viewing the page. Vandalising a static image would be quickly spotted. This is not the case for audiovisual files; unless the preview image is changed, any edits are not apparent until the changed content of the file is played. Depending on the file, noticing such changes may take several minutes of careful observation and listening.

If, instead of modifying the file in-place, the user forks the file to a new filename, then the change may be noticed on Wikipedia since the file reference must be edited. However, the watcher of the old file is left dangling and the new file inherits just one watcher.

Licensing

You can do what you like with media in the public domain, but most content is licensed with an agreement like those produced by Creative Commons, such as CC-BY-SA. A requirement of this licence is that the creator is credited (called attribution) and that, if a derivative work is created, then both authors of the work must be credited. Those credits must be equal in prominence and the new work must include documentation of what was changed. We get this for free when editing the text on a wiki; every edit has a history and one can view the differences between versions with confidence. The edit summary is merely a courtesy, not a legal requirement.

If a media file is edited significantly and a derivative work is created, the author of the derivative work must manually document somewhere the changes they made and update the details on authorship. This could be immensely tedious and its non-automatic nature invites mistakes and omissions, deliberate and otherwise. A further complication is that some of the credit information may be embedded in the video rather than the file description page. A prefix promotional title for the original author will not automatically credit the additional authors and may mislead viewers into thinking that the entire content was the product of one organization or person.

Sourcing

Wikipedia articles are generally written with citations to sources that are embedded in the text and listed at the bottom of the page, called inline citations. For video, this is generally not possible. General citations could be included in the file description page, but these are quite inadequate when compared to the text–source link that we can offer for article body text. Since Commons does not require that educational media be sourced to a reliable publication, it cannot demand that video content be supported by citations. Since Wikipedia is not Commons, Wikipedians cannot demand Commons contributors include citations.

Since WP:V requires that "any material whose verifiability has been challenged or is likely to be challenged, must include an inline citation that directly supports the material", there is a fundamental problem with lengthy videos that cover multiple facts and opinions. There is no technology at present that allows the viewer to stop the video and ask "What is the source for that claim?". Shorter videos that cover a single or few related claims are able to be referenced in their entirety and meet the requirements of Wikipedia's verifiability policy.

Editing

When one edits a Wikipedia article, the new text fits naturally within the old. At most, someone may notice an inconsistent writing style or perhaps a variant of spelling, both of which could be easily amended. For audiovisual media, it is generally not possible to make an edit (other than truncation) that is seamless. A narrator cannot be substituted by anyone else and achieve the same voice-over. Even the same narrator on a different day, in a different room, or a different distance from the microphone, will produce a different recorded voice. One narrator's Scots accent will jump out at the viewer much the same as bold blue text jumps out within the black article text, especially when the original narrator's accent is completely different.

For audiovisual media that has computer-generated artwork, animation, and text, one would need access to the same collection of source materials to provide a seamless edit. This material may be proprietary, however, and are unlikely to be accessible to any editor. For audiovisual media that is created photographically, various factors will influence the look: the lighting arrangement, the camera equipment and lenses, the time of day and location, the post-processing (such as color grading), and so on.

In addition, Wikipedia does not provide the tools for "anyone to edit" these files. Generally, one requires a personal computer (rather that tablet or mobile phone) and complex video editing software (much of which is proprietary) with a considerable learning curve. One may also need software to generate computer artwork or camera equipment to photograph a video. Consequently, the barrier to participation is very high, which departs from the wiki way. Furthermore, Wikipedia permits users to edit without logging in to an account (their IP address is recorded instead); in contrast, Commons does not permit users to upload files without logging in to an account, so edits to media files cannot be made by IP users. The merits of this may be up for debate, but so long as Wikipedia promises to be open for anyone to edit, even without an account, then video content is excluded from that promise.

Even when the original producers of a video make small changes, they can take several hours of work: "To give some perspective, making edits to these videos does not take 2 seconds. The edit we made on your suggestion took a couple of hours of work." (source)

Moreover, the original producers of a video may refuse to make changes because they disagree, do not see the need, or because they feel their target audience (different from Wikipedia's) does not demand it: "We feel your other suggestions are an expansion of the scope of the video, beyond what we want to cover for our target audience. Perhaps down the road if there is a significant demand we can make a second video launching into the detailed intricacies of the disease." (source)

Scope

For an audiovisual clip demonstrating one feature of an article topic, the scope is small. Editors may choose to include the clip or not and the gain and loss is limited to that point feature. It is also significantly easier to replace the clip entirely with an alternative rather than trying to edit the original clip.

For long videos that cover much of the article topic, there is an all-or-nothing problem with the content, and any edits made to it. One cannot fix problematic areas, nor can one accept most of someone's edits but not all of them. This can result in change requests having to be made to the video author, rather than being done in a wiki fashion by any editor.

Promotion

On English Wikipedia, text and images do not contain in-article credit for the authors, nor do they display links to the author's websites, Facebook, or Twitter account. Instead, this information can be accessed by following the contribution history through to the user page and then to a permitted modest amount of personal information and links.

Many videos of longer duration contain prefixing title pages with logos and text indicating the organization that produced the work; and end-credit pages that list contributors, further details of the producer, and promotional links. This is not what Wikipedia is about.

Translation

Depending on the content of the video, it may be difficult to translate. It is hard to replace a narration with another language in a seamless manner. The video may contain text, as well, in which case the video frames containing that text would also need to be edited if the translation is to be complete. If the video displays a person talking, translation has to resort to crude over-dubbing or subtitles, or else find someone else to film.

Adding value

A video that has narration of a script which could well have formed article text is not adding any value other than having someone read something out loud what you could read for yourself. A video with textual graphics is a needlessly convoluted way of presenting words to the reader compared to the body text of an article. A video that contains static graphics (or which move about for no reason other than to entertain) is not adding value more than a static image would in the article body. This is especially true when considering that the value is meant to be encyclopaedic value.

Where video adds value is in offering an audio or animated visual experience that cannot be reproduced by text or by a static image. Such videos are typically short.

Style

Videos may have a style that is not appropriate to an encyclopaedia. For example, the narrator may introduce themselves or welcome the viewer or explain things about themselves that are not relevant to the educational purpose. The tone of the narration and graphics may be jovial and playful when the subject (such as a disease) is anything but that. This may be because the videos were created for a different intended audience than Wikipedia's readers.

Accessibility

For videos that do not match the text of a corresponding Wikipedia article, web accessibility is an important consideration. A full transcript should be available for any narration. The transcript can be posted to the file's description page.

Closed captioning can also improve accessibility, as can providing audio description of visuals that are not thoroughly described in narration. Videos with dialogue should be transcribed into the TimedText system, so that they can be captioned for the benefit of people who are unable to hear the audio or who do not understand spoken English easily (among many other reasons) and also translated for use in all other language projects. Textual labels within videos should be considered carefully, because it makes the videos inaccessible for all non-English viewers and limits re-use.

On Wikipedia, our readers come first; if something places a different audience above them, or prioritizes something other than our readers, then that may be incompatible with the purpose of this project.