Google search results are personalized even when incognito, study finds

It’s a well-known fact that Google has a heck of a lot of user data stockpiled in its servers, and it admits to using info like user location, browsing habits and search history to personalize some of its search results. However, a new study conducted by competitor DuckDuckGo has found that these targeted results are practically impossible to escape.

As part of the study – entitled Measuring the Filter Bubble: How Google Is Influencing What You Click – 87 participants did a search for the political terms "gun control", "vaccines" and "immigration" only to find each individual had markedly different results despite the identical search terms.

The study suggests that this "filter bubble" remains active for each individual user, even when using private browsing (Google’s Incognito window) or when logged out of a Google account.

No such thing as online anonymity

The study was conducted in June this year, when the political scenario in the United States was heating up with campaigns prior to the midterm elections. 

The timing of the study was significant as well. Citing an independent study conducted by the Wall Street Journal in 2012 – which found Google search results significantly influenced the 2012 Presidential elections – DuckDuckGo wanted to confirm whether personalized search results tightened the effects of the "bubble" and influenced people’s decisions.

Is the proof in the pudding?

The study found that "most participants saw results unique to them". First page results varied between participants as well, with some links included for a few individuals, and not available to others. 

Even private browsing and being logged out of a Google account "offered very little filter bubble protection". 

"These tactics simply do not provide the anonymity most people expect," claims DuckDuckGo. "In fact, it's simply not possible to use Google search and avoid its filter bubble."

While browsing incognito or when logged out, according to the results of the study, 68% of participants saw unique results for "gun control", while "immigration" produced personalized results for 57% of individuals. That number jumped to 92% seeing unique results for "vaccinations" in private browsing mode or when logged out.

When browsing on a normal search window, the results were similar – 59% saw unique results for "gun control", 63% for "immigration" and 92% of participants had personalized results for "vaccinations".

Not (rocket) science

While the study is far from scientific and the results potentially biased, it does provide some interesting insight. 

In a comment to The Verge, Google explained that "search results can change by the minute and sometimes even by the second", and that "personalization is done on a small fraction of total number of queries entered into search". 

However, no explanation has been provided on why search results still get the personal touch when logged out or during private browsing, although the tech giant did clarify that it "does not personalize results for incognito searches using signed-in search history".

Google followed it up with a statement to 9to5Google, saying the study was flawed. "This study’s methodology and conclusions are flawed since they are based on the assumption that any difference in search results are based on personalization. That is simply not true. In fact, there are a number of factors that can lead to slight differences, including time and location, which this study doesn’t appear to have controlled for effectively."

Sharmishta Sarkar
Managing Editor (APAC)

Sharmishta is TechRadar's APAC Managing Editor and loves all things photography, something she discovered while chasing monkeys in the wilds of India (she studied to be a primatologist but has since left monkey business behind). While she's happiest with a camera in her hand, she's also an avid reader and has become a passionate proponent of ereaders, having appeared on Singaporean radio to talk about the convenience of these underrated devices. When she's not testing camera kits or the latest in e-paper tablets, she's discovering the joys and foibles of smart home gizmos. She's also the Australian Managing Editor of Digital Camera World and, if that wasn't enough, she contributes to T3 and Tom's Guide, while also working on two of Future's photography print magazines Down Under.