Robert_Charlton - 9:56 am on Sep 12, 2012 (gmt 0)
PS to the above....
Long tail queries with => 3 keywords are missinterpreted by google or they ignore one keyword or they replace one or two keywords with "similar" but unrelated synonyms.
A bell goes off about this one as well.... I think this is Google building those fabled "taxonomies", as tedster so astutely called them. Perhaps mathematically they're "multidimensional paths or flow patterns of user experience", as I've been thinking about them. I've forgotten too much math to say.
=> 3 keywords are missinterpreted is completely consistent with the testing idea, I feel. Perhaps longer and longer tail queries will be going fuzzy for a while. Basically, I think Google is doing what it's done on every algo I've seen it test... it's started with the short, competitive phrases and then gets into longer and more specific phrases. This is also consistent with how artificial intelligence learns. It needs lots of data, and data on long-tail takes longer to gather.
Additionally, I've felt I've been seeing the auto-complete suggestions getting more specific. (Perhaps this is even what's directly or indirectly causing the effect).
All of the above is conjecture, but it's consistent with what I think I've been seeing for a bunch of years now.