Google Shows Personalised Search Results When Logged Out: The “Filter Bubble”

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DuckDuckGo reveals Google still personalises results, even when users are logged out or using a private browsing mode.

DuckDuckGo has written a piece on measuring the “filter bubble”, which details how Google influences what you click.

In this, it describes how Google manipulates search results based on personal data, which involves how links are moved up or down the SERP which necessitates the filtering of other search results.

These are informed by the vast amount of personal information Google has on you, and places you in a bubble based on what Google thinks you are likely to click on.

Essentially, DuckDuckGo studies 87 participants across the US who searched at the same time, logged out, in private browsing mode. They searched for the same terms and repeated them when in non-private browsing mode.

The study shows they saw results unique to themselves – and it could not be explained by location, time, log-ins or other algorithm changes.

DuckDuckGo’s findings are as follows:

  • Most participants saw results unique to them. These discrepancies could not be explained by changes in location, time, by being logged in to Google, or by Google testing algorithm changes to a small subset of users.
  • On the first page of search results, Google included links for some participants that it did not include for others, even when logged out and in private browsing mode.
  • Results within the news and videos infoboxes also varied significantly. Even though people searched at the same time, people were shown different sources, even after accounting for location.
  • Private browsing mode and being logged out of Google offered very little filter bubble protection. These tactics simply do not provide the anonymity most people expect. In fact, it’s simply not possible to use Google search and avoid its filter bubble.

DuckDuckGo claims this creates a filter bubble, which is where Google filters search results based on data, and keeps them in a specific bubble based on what the algorithms think they are likely to click on. Which leads to a number of issues when it comes to certain matters, such as politics and other global affairs.

Google’s Response to Personalised Search Results

Google has hit back at the study, claiming it is privatised, rather than personalised. The changes seen in the search results are related to a number of factors, but not down to personal data to such an extent.

Google say they do personalise search results, but it only occurs lightly and does not change dramatically between people based on personal data. They supposedly do not personalise search results based on demographic profiles. It’s also possible to disable personalisation in search results under the Web & App Activity in a Google account.

Over the years, a myth has developed that Google Search personalizes so much that for the same query, different people might get significantly different results from each other. This isn’t the case. Results can differ, but usually for non-personalized reasons. Let’s explore…— Google SearchLiaison (@searchliaison) 4 December 2018

Google have said:

One of the most common reasons results may differ between people involves localized results, when listings are customized to be relevant for anyone in a particular area. Localization isn’t personalization because everyone in the same location gets the same results…

Localization is extremely useful in making results more relevant. For example, people in the US searching for “football” do not generally want UK football results, and vice versa. People searching for “zoos” in one area often want locally-relevant listings…

Another reason results may differ is when they are customized to be relevant for anyone searching in a particular language. This also isn’t personalization because everyone gets the same language results…
Results might also differ slightly because of how dynamic & distributed our search system is. Our various data centers are constantly being updated with the latest information we have gathered from trillions of pages, along with our latest ranking improvements.

Time is also a factor. Those who search a few hours or even minutes apart may see variations as new & updated material is added to our search engine. In particular, our “Top stories” section, which is never personalized, can change significantly in a short period of time…

Results may also differ slightly because of platform. On mobile, we prefer fast-loading, mobile-friendly pages, if content on those is as good or better than desktop versions. If you’re using Android or iOS, we may list apps that are appropriate for the respective devices.— Google SearchLiaison (@searchliaison) 4 December 2018