Google Webmaster Tools - Can keyword position be incorrect?

[John_Lee]

I write a blog (blogspot). Just yesterday I checked onto my webmaster tools report of "top search queries". and at the no. 10 positon, I found a keyword (quite competitive) and it's position was 6, impression 2% only. Three days ago, there was a very highly competitive keyword at the top with 14 % impr. and position 21. That's obivious that I was (am still :)) excited, but my site doesn't appear in the google at all. But for that first keyword with position 6, my site appears at 2nd position at YAHOOOO!. But I want that to appear in GOOGLEEE!. :D
Could this be due to changes in Google database being made lately, could this appear in near future.

Also at the bottom of the "top search queries" table, there is like this keyword [[[["inanchor:"my keyword" intitle:"my keyword" inurl:"my keyword"]]]],,,Now what's dat? Have anyone had this kinda thing going on these days?

[Jane_Doe]

I think that is a bug they have in webmastertools. I've noticed the same thing. If I ever really ranked for some of the one word terms they report my traffic would be much higher than it is.

[FranticFish]

I always used to find (before personalised search) that WMT would show positions a little lower than those I would see searching in Google.

Remember also that
(a) you can filter the data to exclude image search and country-specific Googles
(b) even when you do this the data is averaged out across all DCs and the smallest period is a week

Who knows when they actually take the sample to show in WMT and whether or not that coincides with some algo tweak or other sort of data spike that might favour your site for a short period of time.

[UserFriendly]

I'm guessing that these numbers must be estimates / approximations.

Most of my data just says "<10" which suggests that an element of imprecision is involved.

[Acrill]

I think the confusion arises because WMT lists single-word keywords that were triggered by your site as part of expanded broad match queries. Unfortunately, WMT doesn't distinguish between broad, phrase and exact queries in the 'top search queries' list.