Understanding Google Datacenters and Ranking Differences

[feiman]

I'm trying to understand the relationship between what the datacenters report and what is actually displayed when you do a live search. For one of our key industry terms, a website shows up on our live Google searches as ranked #1, but when I run a search on one of the datacenter check tools, this site consistently shows up as #8 or #9 across the board.

I've tested this from different computers and different IP addresses (obviously not logged in to my Google account) and for the life of me I can't figure out why this site would be #1 when I do a search, but #9 when I check them on the datacenters.

Any ideas how/why this is happening?

[dstiles]

In the past I've seen three different results on three different computers here, all browsing from the same IP, all search terms identical. Still get different results from time to time.

[tedster]

I think of the datacenters as providing raw information, but it then goes through a good number of other potential filters, such as geo-location, time of day, day of week, various kinds of user-testing, and who knows what all - maybe even things like the yo-yo effect or the apparent traffic thresholds.