bingdude - 6:17 pm on Jul 6, 2011 (gmt 0)
That is a bold assumption to make. Do you really think there is NO other explanation? As discussed all over these boards, this is a dangerous metric to use when determining a searcher's satisfaction with a particular page for a particular query. I often search for information, find a list of pages for my query, click on one, see the phone number or other information I'm looking for and get right out of there.
Fair assessment, and I should provide some more insight here.
If this were the only signal used, I would agree with you about the assumptions and potential danger - but keep in mind we examine about 1,000 signals when determining how to rank a page.
...and you state "I often search for information, find a list of pages for my query, click on one, see the phone number or other information I'm looking for and get right out of there."
You leaving a website is not something we see - in fact, if you left the website, we'd assume you were more satified than less satisfied simply because you didn't come back to us. Remember, we're looking specifically at the "back" action here. Are you saying you'd find the phone number, then hit back to come back to the SERP, then go about your business making the call? Not a pattern I'd say "most" people would follow (IMO).
Other websites have contact forms on the destination page that only take 20 seconds to complete and then the user is done, they have found what they want or accomplished the task they set out to accomplish. Hiding web pages that efficiently provide exactly what the searcher is looking for is a terrible way to provide excellent search results. The opposite can also occur - that webmasters will be encouraged to build pages that are always at least 1 step away to keep users clicking.
To clarify for you, we're talking fractions of a second, not 20 seconds. How many times have you clicked a result and known immediately the page wasn't what you were after? (Could also happen through the unfairness of a user scanning a page too quickly and missing the data you have and that they want - ths is a UX/design issue, but nets you the same problem.)
If you were looking for a phone number or contact info, and queried for that, we'd know your intent. Seeing a phone number only takes a few seconds, so coming back after asking for a phone number and seeing one wouldn't be an issue as the need was met. Even hitting a home page, then clicking on "contact us" to see the number, and THEN hitting "back" a couple of times will result in a longer session.
What's also worth remembering is we see these patterns millions of times an hour, and can test and fine tune results based on that volume of data.
It's that quick, immediate "back" action that we're interested in. Yes, you could argue in isolated instances this is not a realistic metric for a specific exmaple, but across the volumes of queries we see, it's valid.