Please forgive if this is ground covered previously; I’ve only just subscribed to this list.

I wonder how this would apply to my home wiki (en.wikibooks) and other wikis where editing is slow. Wikipedia has a constant deluge of edits from vandal IPs up the “editing hierarchy” through to the most trusted editors. Wikibooks, however, has a far smaller group of regular contributors, (almost) all of which have a high reputation. Nonetheless, modules are often untouched for weeks or months at a time – this is simply the nature of the textbook-writing beast.

As I understand it (which could be totally off-base), this algorithm requires editing of the text to determine trust. So what happens when the text isn’t edited for months at a time, as is the case with many of our books?

In the absence of editing, it seems like explicit metadata wins out, since there *is* no implicit metadata to use (or at least, much much less).

From this point of view, it seems the only outstanding downside to FlaggedRevs is the workload created. I wonder, though, if on Implementation Day, all current revisions (or do last week’s revision or whatever) could be tagged as an “initial” state (just so there’s some starting place) and then we go from there. For enwiki, there would be a flurry of people going though and making explicit choices to flag a revision. And on enbooks, there would be (much) slower progress in the same vein. This may not be advisable on the large wikis. Wikibooks, however, has a relatively clean doormat. We have vandalism, but it doesn’t tend to hang around, so setting an initial state would probably result in much/any vandalism getting caught in the net.



From: Luca de Alfaro []
Sent: December 2, 2007 2:10 PM
To: Wikimedia Quality Discussions
Subject: Re: [Wikiquality-l] Implicit vs Explicit metadata


In the trust algorithm I am implementing with my collaborators (mainly Ian Pye and Bo Adler), text can gain top trust only when top trust authors essentially vote for it by leaving it there, so there is not so much difference in the "voting" part wrt flagged revisions.  The main difference is that in our algorithm, the text that is unchanged inherits the trust from the text in the previous revision --- no need for re-voting.  The algorithm has been described in a techrep .

This week, we will open access to a demo of the whole Wikipedia, as of its February 6, 2007, snapshot, colored for trust.  We are now working towards making a "live" real-time version, so that revisions can be colored as soon as they are created.
Currently, people can "vote" for the accuracy of text only by leaving it unchanged during an edit.  We plan, for the live implementation, to give an "I agree with it" button, which enables people to vote for the accuracy of text without the need for editing it.

We have also considered selecting as "stable" revisions revisions that are both recent, and of high trust.  We agree with the original poster that this may have some advantages wrt flagged revisions:

When the demo will be available later this week, you will be able to judge whether you would like to select recent revisions that are of high trust.   The algorithm we have now is not perfect, and we are considering improvements (we will update the demo when we have such improvements), but in general we share the opinion of the original poster: an automatic method for flagging revisions can be more accurate (preventing flagged revisions from becoming out of date), and less painful (no need to spend time flagging).


On Dec 2, 2007 7:32 AM, Waldir Pimenta <> wrote:

I agree with you, Aaron. Flagged Revisions by *trusted users* is indeed better than automatic trustworthiness evaluation. Ratings by everyone, probably wouldn't be. But I'd say, following your own words ("It has the advantage of leading to a burst of pages with "trusted" versions without adding any real workload whatsoever"), why not having this the default option if there is no flagged version available (yet)? Perhaps with a note, shown to people who choose to view stable versions (or to all unlogged readers, if the stable versions are to be default), similar to the one that we see when we're consulting an old revision. It seems to me that this is better than showing the current version if the flagged one doesn't exist, or is too far away in the revision history. (with the "stable view" enabled, that is). Also, picking a revision with no "highly dubious" parts sounds a good approach to me :)



On Nov 28, 2007 12:40 AM, Aaron Schulz < > wrote:

Flagged Revisions and Article Trust are really apples and oranges. I have contacted them, and let them know I'd be interested in getting this up into a stable extension; they are not in competetion.

Anyway, my problem with that article about implicit vs. explicit metadata is that a)it assumes any random user can rate, b)you are measuring simple things like interesting/cool/worth reading, and c) you don't care too much if bad content shows sometimes. The problem is that none of these hold true here. Flagged Revisions uses Editors/Reviewers, it mainly checks accuracy, and we don't want high profile pages/living people articles/highly vandalized pages as well as eventually anything to show up with vandalism. Going to "George Bush" and seeing a vulva for the infobox is not ever acceptable (I don't even know if Article Trust rates images), even if the vandalism is darker orange or whatever.

The Article Trust code looks at the page authors. To a large extent, this quite good at highlighting the more dubious stuff. On the other hand, things become less orange with new edits (since it is less likely to be crap). The downside is that cruft and garbage can get less orange and appear more valid. This can easily happen with large articles and section editing. That makes this it very hard to use for quality versions. Flagged Revisions would be better at that.

Vandalism can take days to clean up. If AT is to be selecting the best revision, it should trying to check both global average trust of each revision as well as it's worst parts. This way it could try to pick a revision with no "highly dubious" parts. Having looked at the article trust site, I'd have a very hard time demarking what the maximum untrustworthyness a section can have would be wihout being under or over inclusive. I'd go with underinclusive. It does seems reasonably doable at least. It has the advantage of being fully automatic, so there will be a huge number of articles with a "most trusted" (for lack of a better name) version. It won't necessarily be stable, and could be quite outdated though. In fact, even people who would otherwise have Editor (basic review) rights would have their changes go to the trusted version on edit. This would eat too much away at editing incentive if the "most trusted" version was the default if even experienced users could not directly control it.

So to sum up. Having a link to the "automatically selected most trustworthy" version seems plausible, as long as it is not the default. It has the advantage of leading to a burst of pages with "trusted" versions without adding any real workload whatsoever. The AT team would have to whip up and test around with some algorithms though.

-Aaron Schulz

> Date: Tue, 27 Nov 2007 20:29:51 +0000
> From:

> Subject: [Wikiquality-l] Implicit vs Explicit metadata

> I am sure this has already been discussed, but just in case, here goes
> my two cents:
> The post in
> explains why implicit metadata (like Google's PageRank) are better
> than explicit metadata (Like Digg votes).
> Making a comparison to Wikimedia, I'd say that Prof. Luca's trust
> algorithm is a more reliable way to determine the quality of an
> article's text than the Flagged Revision Extension.
> However, the point of the latter is to provide a stable version to the
> user who chooses that, while the former displays to which degree the
> info can be trusted, but still showing the untrusted text.
> What I'd like to suggest is the implementation of a filter based on
> the trust calculations of Prof. Luca's algorithm, which would use the
> editors' calculated reliability to automatically choose to display a
> certain revision of an article. It could be implemented in 3 ways:
> 1. Show the last revision of an article made by an editor with a trust
> score bigger than the value that the reader provided. The trusted
> editor is implicitly setting a minimum quality flag in the article by
> saving a revision without changing other parts of the text. This is
> the simpler approach, but it doent prevent untrusted text to show up,
> in case the trusted editor leaves untrusted parts of the text
> unchanged.
> 2. Filter the full history. Basically, the idea is to show the parts
> of the to the article written by users with a trust score bigger than
> the value that the reader provided. This would work like slashdot's
> comment filtering system, for example. Evidently, this is the most
> complicated approach, since it would require an automated conflict
> resolution system which might not be possible.
> 3. A mixed option could be to try to hide revisions by editors with a
> lower trust value than the threshold set. This could be done as far
> back in the article history as possible, while a content conflict
> isn't found.
> Instead of trust values, this could also work by setting the threshold
> above unregistered users, or newbies (I think this is approximately
> equivalent to accounts younger than 4 days)
> Anyway, these are just rough ideas, on which I'd like to hear your thoughts.

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