+ People generally tend to miss the point that Incognito doesn't prevent sharing the IP of the user.
+ I think DuckDuckGo's study missed out using VPN in their analysis. i.e., SignedIn vs Incognito vs (Incognito+VPN)
One thing that caught my eye was Google's response about Incognito:
> The company did confirm that it does not personalize results for incognito searches using signed-in search history, and it also confirmed that it does not personalize results for the Top Stories row or the News tab in search.
Since it's a corporate reply, the standard question is what's not present: a statement that Incognito isn't personalized, or isn't personalized beyond device type and location. Perhaps I'm too cynical, but "we don't personalize using X" parses as "we do personalize in other ways".
IMO the issue is not google using IP-based location info. The issue (if there really is one) is people assuming/believing the internet hides their location.
To me this sounds reasonable. A very large number of searches are locality based, and it is entirely reasonable to localize them based on IP address (and - as you note - the device type).
It's also reasonable to customize based on recent (session based) search history (refinements, spelling corrections, etc).
The difference between this and personalization seems mostly about semantics IMHO.
I wish this was trivial to disable. I regularly search for things where I want the global result, and instead get weird local results that I don't care about. It's much easier to narrow a global search to a local one by adding an appropriate region name to the search than it is to expand a local search to a global one via search terms.
But broadly, I see three bases for objecting to these changes.
First is the lack of user control. Like many other people in this thread I often want to turn off or 'rehome' localization, not just for weird developer use cases but for obvious stuff like "I'm about to travel and want results for that location". Disabling session-based changes is a rarer desire, but comes up sometimes when a correction or topic change is interpreted as a refinement that's biasing results. Fortunately, resetting Incognito should manage that. (I've never actually wanted to bypass device type adjustments except for dev work.)
Second is inadvertent bubbles. It's easy to imagine content-neutral rules like "show fast and mobile-friendly pages to smartphones" correlating with a meaningful content difference, and the same for location. Hard to really blame Google here, but again it'd be really nice to have the option of a "stop helping" setting.
Third is Google-driven bubbles. Some of the DuckDuckGo examples showed effects like national newspaper articles on a search for 'immigration' getting reordered, or pushing above and below non-news sources. (We can't know if that was caused by location or device type, but let's look at the case where it was.) That doesn't look like basic localization, it looks like non-local results being adjusted based on user location.
This wouldn't have to be anything purposeful; if you add location into your training set and reinforce on the usual 'success' metrics (e.g. first result clicked, final result clicked), you could easily learn that people in NYC and Houston have different behavior patterns and display accordingly. It's open to debate whether this is a bad thing, but it's certainly not what most people (including the Googler who responded to the article) mean when they say "localization".
Is there? I was under the impression that Incognito and its cousins generally still accept and preserve cookies for the duration of the temporary session. This means that for this purpose, there isn't really a difference.
In this study, my understanding is that result personalization carried over from a normal browsing session into the clean, Incognito session, likely due to IP correlation or possibly through User-Agent strings. So while Incognito has its own context that is wiped once the session has ended, the result personalization didn't need anything saved in the browser to recognize who you are.
Try this: https://panopticlick.eff.org/
Specifically, check out the "fingerprinting" details.
In a normal (not Incognito) browser window, you don't have to be logged into Google for Google to read Google cookies. Logging out doesn't make you anonymous; they still know who you are.
Try this: https://panopticlick.eff.org/