Google has unveiled Hummingbird algorithm – an upgrade to the way it interprets users’ search requests.

Hummingbird is the first major upgrade for three years.

The new algorithm has already been in use for about a month, and affects about 90% of Google searches.

At a presentation on Thursday, Google was short on specifics but said Hummingbird is especially useful for longer and more complex queries.

Google stressed that a new algorithm is important as users expect more natural and conversational interactions with a search engine – for example, using their voice to speak requests into mobile phones, smart watches and other wearable technology.

Google has unveiled Hummingbird algorithm, an upgrade to the way it interprets users’ search requests

Hummingbird is focused more on ranking information based on a more intelligent understanding of search requests, unlike its predecessor, Caffeine, which was targeted at better indexing of websites.

It is more capable of understanding concepts and the relationships between them rather than simply words, which leads to more fluid interactions. In that sense, it is an extension of Google’s “Knowledge Graph” concept introduced last year aimed at making interactions more human.

In one example, shown at the presentation, a Google executive showed off a voice search through her mobile phone, asking for pictures of the Eiffel Tower. After the pictures appeared, she then asked how tall it was. After Google correctly spoke back the correct answer, she then asked “show me pictures of the construction” – at which point a list of images appeared.

The news was announced at an intimate press event at the Silicon Valley garage where founders Sergei Brin and Larry Page worked on the launch of the search engine, which is fifteen years old on Friday.

At the event, Google also announced an updated search app on Apple’s iOS, as well as a more visible presence for voice search on its home page.

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