This is an example of how a Wikipedia article can be marked up to display provenance. It uses the actual history text from that article. Any highlighted text displays the author and date of a change upon hovering your cursor over the text, and all changes are differentiated by shades of colour that are different from their surroundings.

Interesting edge cases

• Changes in formatting cannot be displayed very well. In the first sentence of the example, the bold formatting was added to the word "provenance" in a later revision than the word itself. The approach used here is to tag the entire area affected by the formatting change, but that may be difficult to implement. Another option is to simply ignore formatting changes, as they contain little-if-any important data. Alternately, the entire page can be displayed in wikitext.
• Hyperlinks are not handled very well in this example, as the "title" XHTML attribute used to display the revision information is overridden by the "title" attribute Mediawiki adds to all hyperlinks. This would not be a problem in a full implementation, except for non standards-compliant browsers. This is rarely a problem in the body text, as the surrounding text is usually changed in the same revision, however it is a problem in the External Links section.
• This example shows all text which has been removed, rather than replaced, as the character ± character. This, of course, isn't strictly necessary.

The example

On the Wikipedia, provenance is the origin of material that appears in articles. Provenance has been a controversial issue on the Wikipedia from its inception. As the Wikipedia has grown larger published concerns about provenance have also grown. (See the external links below.) One of the more prominent critics has been Robert McHenry (the former Editor in Chief of the Encyclopedia Britannica) who suggested that the Wikipedia is like a public toilet where what you find in a Wikipedia article is whatever the last user deposited!

Intellectual provenance has bee a traditional concern of academia. Academics study the intellectual heritage of ideas, concepts, methods, theories, etc. Specifically, they are concerned with properly attributing work in their own field of study. So they question how this can be done for the Wikipedia. For example should academic credit be given for contributions to the Wikipedia?

Provenance has at least two aspects: source and time. (See below.)

Providing provenance has proven to be controversial. Objections have included the following, e.g., from Wikipedia:Village pump (proposals):

• It is technically impossible. (But see proposals below.)
• No one wants it. (But see the articles in the external links below.)
• An article is a joint effort by the community that should stand as a whole without its parts being viewable as to their provenance. It seems to go against the spirit of the way articles have been developed in the past, where we're all in it together and no one lays claim to the work. Editing is really an interactive joint enterprise and should not be viewed as minuscule intervals that do not reflect each real contribution.
• If an article is viewed as intervals with individual ownership, it will affect the process of cooperation on the article, maybe adversely. It allows some users to take prominence over others, which again goes against the spirit in which Wikipedia operates now.
• You don't really know who contributed each interval because people can choose any user login they want.

Proposals for providing provenance have been made and discussed on Wikipedia:Village pump (proposals).

Source provenance

On Wikipedia:Village pump (proposals), Pseudo Socrates made a proposal to provide source provenance by placing a Source Provenance button on the history page of each article that would produce a dynamic page that was a version of the current article modified as follows: Each interval of text would be preceded by a source link that would link to an article in the history where the text following the link first appeared in the editing history of the article. The name of the source link would be source for that version (log in name or IP address). At the bottom of the dynamic page the following notice would appear:

  The name of each link above was derived from the second
  column, "i.e.", source (login name or IP address), of the±
  history page of the article for which this page was produced.
  Clicking on a link will produce a dynamic page that shows
  a (previous) version of the article in which the text following
  the provenance link appears.  Of course the source may not be the real
  the real author of any of the text in an article that results from their edit.

Temporal provenance

On Wikipedia:Village pump (proposals), Pseudo Socrates made a proposal to provide temporal provenance by placing a Temporal Provenance button on each article that would produce a dynamic page that was a version of the current article modified as follows: Each interval of text would be colored according the following algorithm: Text of vintage less than 24 hours would be colored red, vintage more than 24 hours but less than one week would be colored green, remaining text would remain black.

• A Criticism of Wikipedia Now Exceeding a Scream
• Why Wikipedia Must Jettison Its Anti-Elitism
• Wikipedia Faces Growing Pains
• Wikipedia: Me on boyd on Sanger on Wales