It is pointed out that although Google logged out from the account, Google changed the search result to individuals

When searching on Google, the content displayed there is slightly different for each individual, even if the user is logged out from the account, the results of the survey that "personalized" search results are indicated will be announced It is.

Measuring the Filter Bubble: How Google is influencing what you click
https://spreadprivacy.com/google-filter-bubble-study/

Google personalizes search results even when you are logged out, new study claims - The Verge
https://www.theverge.com/2018/12/4/18124718/google-search-results-personalized-unique-duckduckgo-filter-bubble

It is Google's rival service " DuckDuckGo " that announced this survey result. Unlike Google etc., the company has a policy not to sell each user's data as advertising tools.

DuckDuckGo - Simplify privacy.
https://duckduckgo.com/

The survey was conducted in June, 2018, and when we searched Google for three key words "Gun Control", "Immigration", "Vaccinations", which are divided broadly among people Compare the results of. Both are the keywords that DuckDuckGo thought was not so much influenced by the time and place of search. When 76 keywords and 87 searches were performed with these keywords, it was revealed that the search result was divided into 62 patterns.

At the time of investigation, I first searched without logging in to a Google Account, and then I searched the same contents even when I logged in later. From the result, it is not possible to see variations in search results with unlogged logins that are not tied to individuals, but the result is divided when it is said that Google is performing personalization in some way DuckDuckGo It is a claim of. In addition, it also points out that "filter bubble" will occur that will only collect information with high affinity for you in the user's search results.

Meanwhile, we dispute the results of this survey. The biggest point is that "DuckDuckGo's survey is based on the premise that" Google is personalizing even anonymous users. " Google argues that when returning search results to the user's browser, it does not reflect the impact of searches made at the time of login in the past. Search results are not always consistent, especially for topics with high news content, the results are sometimes updated in minutes, sometimes in seconds.