Robert_Charlton - 1:39 am on Aug 24, 2012 (gmt 0)
Duane has given some extensive comments about they're user-data signals that sound like browser data to me (did the visitor scroll, hover on a link, bookmark, etc? During those sessions, Matt did not chime in for Google's POV.
I've assumed user metrics are at play, at least wrt the algo. I don't think they have much to do with url discovery (see footnote below about this)....
Regarding the user engagement signals picked up for the algo, though, take a look at this thread in April 2011, where Brett posted thoughts about possible data sources. He does include Google's toolbar and browser in his list...
Panda Metric : Google Usage of User Engagement Metrics
Many of Google's tests that can be readily observed involve user behavior in serps, and don't necessarily involve the specific browser itself, which is what I think we're discussing here.
Both Google and Bing have search histories which can be disabled. These "search histories" are likely treated differently from the browser histories of their respective company browsers.
Bing's official "Search History" is cookie-driven, browser specific, and can be disabled... but it's on by default unless you turn it off for that browser. They're not tracking an account... they're tracking a Bing searcher on a browser.
Google is IMO using both cookie based data as well as account-based data... and if you want to, say, set preferences or disable "Web History" on Google, you in fact need to stay signed-in to your account to do that. That has given me what appear to be the most neutral results I've seen.
I'm guessing that if you stayed signed in and did not disable Web History, the personalized search data that Google collected might (in the aggregate if signals were strong enough over time) also eventually affect everybody's results... say as in the case of searchers returning to the serps and showing signs of satisfaction or dissatisfaction in subsequent behavior. The point of my earlier question was that this is not browser-specific... it's account-specific... so Chrome itself wouldn't be the tool collecting the data.
Just guessing here... it sounds from what Matt said to bhartzer that Google would not be using Chrome's browser history. That's great, as it's a drag to constantly flush these things. I don't know, though, exactly what Duane has said about whether Bing might be using IE's browser history.
I feel that Google in general is so unclear in its privacy documentation about what's going on that they're probably creating much more paranoia than is really necessary. It looks like Google is beginning to redo some of this material, but these help files are generally self-serving and vague.
In light of Matt's comments, I feel there's more reason to worry about the privacy implications of Double Click cookies than about Chrome... though I really don't know whether these are used in the organic algo.
Regarding url discovery, see the latest discussion about this here...
How has Google found a page with no links to it?