Search engines such as Google take just seconds to find information and have become a part of our everyday lives. But what comes out of the search is highly personalised, based on data they're collecting.
Once upon a time, there were dictionaries, books, magazines and the phone. But now when you need to look up the capital of Kyrgyzstan or a cheesecake recipe, there's an Internet search engine.
Search engines have a huge impact on what information gets through to users. And since people search for things that are personal and private, it makes sense to educate yourself about how these search results are generated – even if the actual search algorithms are usually business secrets.
For cost reasons, only a few search engines actually maintain their own index – a collection of keywords that can be quickly searched to find pages with the desired content, explains Christian Pietsch from the organisation Digitalcourage.
The search engines with their own index are quickly listed, he says: "Google, Bing, Yandex, Baidu. None of them are known for their transparency."
Many providers instead use the search technology of Google and the others, and integrate it into their portals, according to German consumer goods tester Stiftung Warentest. For example, Qwant and Duckduckgo rely on the technology of Microsoft's Bing search engine.
Stiftung Warentest took a closer look at some search engines earlier this year and found that market leader Google brought in the best hits with standardised queries but also collected the most user data. The testers also criticised Bing for its handling of user data.
The test's winner was Startpage.com, which describes itself as the world's most private search engine. The Dutch-based company says it doesn't log, track or share the personal data of users.
Stiftung Warentest found that its search results were good although not as good as those of Google.
In terms of your data privacy, does it really matter which search engine you use and on which device? The answer is yes.
For example, Google uses the IP address of the user's computer to determine its approximate location. The address is not personalised, the company says, but is used to display locally relevant search results.
Your individual search history can influence the results, but the user would have to be logged into their Google account for this to happen, the search engine giant says.
You could get marginally different results depending on whether or not you're logged into your account when you carry out a search.
Bing also stores users' search activity using cookies and other means, a spokesperson for Microsoft said. Search results are personalised based on these results. The mechanisms that lead to this personalisation are subject to the applicable data protection laws.
To prevent personalisation, Stiftung Warentest advises people to use the incognito mode in their browser, which stops cookies and browsing history from being saved.
Google searches while you're logged into your Google account are saved, but they can be deleted, and you can also disable personal data storage.
Klicksafe.de advises people not to search when logged into their accounts and also to regularly delete their browsing history and cookies.
Pietsch recommends installing advertising and tracking blockers as browser extensions. The options include uBlock Origin, NoScript, Privacy Badger and Ghostery.
There are also meta-search engines such as Searx and MetaGer, which are open source and trusted. – dpa