Why Do Google Hit Numbers Vary?

Supa-Fly writes "I have a question about some conflicting results with the search engine google. I did a search for "pictures of mountains" and got exactly 1 million results. My friend did the same search (from the same office)and got 1,010,000 results. A second friend did the same search as the last 2 and got 1,020,000. These have not changed and every person gets the same results each time. My question is what is up with the discrepancies on google's search results?" Since this question is hard to answer from the outside, Craig Silverstein of Google kindly supplies his best answer to this question, below.

Craig writes: "Thanks for the great question. We get this from time to time and hopefully I can clear up some of the confusion. The number of estimated pages listed to the top right of a Google search results page is indeed, an estimate. It's a good estimate but still, an estimate.

There are many reasons why one might see a difference in the estimated number of pages returned for the same query. It's most likely the queries made by your co-workers were sent to different Google datacenters in what appears to have been a round-robin fashion. The index at any given Google datacenter can change slightly over the course of a day (each index is refreshed completely every three to four weeks). Depending on which datacenter finishes a query, the estimated number of results may vary.

Without having direct access to your environment it is hard for me to tell for sure, however, I believe this is the case."

Comments

Interesting Google phenomena

[ergo98]

Several weeks back I happened to mention a very nice new restaurant in Toronto on one of my pages, and within days shot to the #2 position on Google when searching for several variants of this restaurants name. I knew this by the fact that suddenly I was seeing closing on a hundred hits per day of people looking for this restaurant. Note that this restaurant has such a unique name that there are only around 5 pages of links in all anyways. Anyways suddenly the hits entirely stopped, and a search on Google found my page was purged from the database: Despite it being a unique name with few hits, it no longer even registered. A week later suddenly it was back in the #2 spot again.

No idea why this happened, but it is entertaining to see it vary.

Re:Interesting Google phenomena

[lemox]

It's called the "Google Dance", which is mentioned in an earlier comment.

googledance

[wfmcwalter]

There's a number of websites (dare I say "fansites") devoted to the study of google result variance - the so-called googledance.

this and this

Some different results

[jsprat]

Here's what I get:

"pictures of mountains" 986,000
"pictures of of mountains" 1,010,000
"pictures of of of mountains" 1,020,000

Two of these pages had a different top-ranked link.
Funny thing, all three times Google told me "of is a very common word and was not included in my search", but it made a difference!

Regardless of these results, Google is the best search engine. Period.