Issue: Similar content based upon tags and forums

It's much easier to change the "Similar Content" method in VaultWiki than vBulletin, because the data would be processed on the fly if we tell the cache to expire. We used the similar threads method because it was a question of proof of concept by a deadline. When I saw the code for Similar Threads, I was surprised myself and realized just why and how inaccurate vB's results were -- it only matches against other thread titles, rather than doing any sort of contextual matching. We intend to do a lot of contextual stuff in VaultWiki 4, so I expect this method to be changed when we can dedicate more time to the feature.

Thats good news.

Improved this function somewhat by excluding words that are usually ignored by search ("a", "the", "one", etc) and by applying the minimum search word length. If most terms are removed by this cleanup, then similar content will not be calculated, since it's likely none of the results will be relevant anyway. Overall, these changes should improve relevancy slightly.

I am still trying to come up with a way to apply a tag filter -- not sure whether to do it before or after the title filter -- and whether there is a way to do it without introducing lots of queries. Anyway a tag filter would only benefit vBulletin 4, since it's the only platform with cross-platform tags right now.

The forum filter has the potential to make the biggest improvement for relevancy right now (also blog category and CMS category filters). But I am struggling with the implementation. It seems to me that someone would actually have to define what forums are relevant to the wiki, which means a separate admin interface just for the benefit of one sidebar block. The other way is to run a title comparison between forums and areas and cache the results, but this might end of making the results even less relevant by possibly excluding more relevant forums.

Since the admin interface option would have to be tied to areas, tucking it away as another control in the area manager might make it seem less of a waste of menu real-estate.

Excluding results from specific forums per area would be useful.
I have various 3 letter article titles.

Its highly likely that XF2 will have cross content tags, because xenforo gallery has content tags and has become an official addon.
Maybe its best to schedule the XF tags part for XF2.