* Google submits many more searches with it's instant AJAX search-as-you-type
* Google's speed allows users to hone in on better search results by tweaking terms, whereas Bing/Yahoo users don't waste their time with a 2nd search
* Google displays the answer right on the results page with superior semantic analysis, nullifying the use of a clickthrough
* Google's tools (such as "define:", math like "4+1.078", and conversions like "45cm in inches") are well-known and people look to Google itself for answers, not secondary sites in results
* If Google's users are more "tech savvy", they may use search qualitatively differently than Bing users (related to the above explanations)
* Google users click on Google Ads more than Bing users click on Bing ads - are ad clicks tracked?
Of course, these could all be wrong. But worth looking into or acknowledging in the research if they already had.
If Google corrects a spelling mistake for a user: did you mean x? than that is counted as a bad user experience. If a user gives up on Bing and goes to Google to refine her search, than that is counted a good user experience for Bing.
Another confound I would note is that Bing is highly specialized in certain queries, and that users may select Bing for the queries they know will result in specialized results, and use Google for everything else.
Another one based on the logic that Google's users are more "tech savvy" (which I believe they, on average, are):
* A larger percentage of Bing users are doing "time-saving" searches, such as "hotmail" and "facebook", where they know the first result is what they want even before they search.
And extending that logic - a tech savvy audience will be more likely to have more complex results. It's not hard to give searchers want they want when they're looking for "superbowl results" or "justin bieber".
Here's what I observe among my non-tech friends: they have Google as their homepage. If they want Facebook, they type "Facebook" into the search box - even tho' typing it into the address bar would do the same thing. If they come across a PC that's not on Google, then they go to Google using the address bar and proceed as before.
* Google submits many more searches with it's instant AJAX search-as-you-type
* Google's speed allows users to hone in on better search results by tweaking terms, whereas Bing/Yahoo users don't waste their time with a 2nd search
* Google displays the answer right on the results page with superior semantic analysis, nullifying the use of a clickthrough
* Google's tools (such as "define:", math like "4+1.078", and conversions like "45cm in inches") are well-known and people look to Google itself for answers, not secondary sites in results
* If Google's users are more "tech savvy", they may use search qualitatively differently than Bing users (related to the above explanations)
* Google users click on Google Ads more than Bing users click on Bing ads - are ad clicks tracked?
Of course, these could all be wrong. But worth looking into or acknowledging in the research if they already had.