A new study (via Wired) from Google rival DuckDuckGo charges that Google search personalization is contributing to “filter bubbles.” Google disputes this and says that search personalization is mostly a myth.
The notion of filter bubbles in social media or search has been a controversial topic since the term was coined a number of years ago by Eli Pariser to describe how relevance algorithms tend to reinforce users’ existing beliefs and biases.
Significant variation in results. The DuckDuckGo study had 87 U.S. adults search for “gun control,” “immigration,” and “vaccinations” at the same time on June 24, 2018. They searched both in incognito mode and then in non-private-browsing mode. Most of the queries were done on the desktop; a smaller percentage were on mobile devices. It was a small test in terms of the number of participants and query volume.
Below are the top-level findings according to DuckDuckGo’s discussion:
- Most people saw results unique to them, even when logged out and in private browsing mode.
- Google included links for some participants that it did not include for others.
- They saw significant variation within the News and Videos infoboxes.
- Private browsing mode and being logged out of Google offered almost zero filter bubble protection.
The DuckDuckGo post offers more in-depth discussion of the findings, as well as the raw data for download.
Comparing the variation in search results
My test found minor differences. I searched “gun control,” “immigration,” and “vaccinations” in private mode and non-incognito mode. I didn’t find the results to be substantially different, though there were some differences in the SERP.
In the case of “immigration” (above) you can see there’s an ad in the incognito results but none in the non-private results. The normal results also feature a larger Knowledge Panel and “people also ask” search suggestions, which didn’t appear on the first page in the incognito results but did appear in subsequent searches on the same term.
Google Search Liaison Danny Sullivan responded to the study with a series of tweets explaining that there’s very limited personalization in search results but that the company does show different results because of location, language differences, platform and time (on occasion). He said, “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.”
In September this year, Google told CNBC that it essentially doesn’t personalize search results.
Why you should care. Non-personalized search results make the job of SEO practitioners easier because they can better determine the performance of their tactics. Google doesn’t consider “localization” to be personalization, although many SEOs would argue that it is. On mobile devices, proximity is widely seen as a dominant local ranking factor.