Microsoft reveals Cortana, Windows Phone’s answer to Siri

After a lot of leaks and speculation, Microsoft has finally unveiled its virtual assistant for Windows Phone, which goes by the name of Cortana.

Redmond's answer to Siri and Google Now, the voice-powered services on iOS and Android, has been a long time coming – but apparently, that time has been well spent fine tuning Cortana's responses.

At least that's the case according to one AI expert who the BBC spoke to, Steve Young, who is professor of information engineering at Cambridge University.

Young observed that: "Siri and Google Now have a limited ability to extract the actual meaning from the words that somebody speaks... if you ask it [Siri] about something that it's not been previously programmed to understand it simply passes the word into a search engine."

"I understand that for Cortana Microsoft has done a lot of work to automatically learn a much wider range of semantics... so the expectation is that it will be able to understand a good deal more."

Joe Belfiore demonstrated Cortana at Microsoft's Build conference, and at first glance, it does indeed appear to be a pretty clever piece of programming. For starters, when summoned it will automatically offer up suggestions of what the user might be looking to achieve based on their location, and previous usage pattern.

As had been previously rumoured, it can also tap into user data, if allowed – such as the calendar, emails, browsing history and so on – to build up information, again to allow it to better serve and anticipate user requests. Though some might not like the potential data mining angle here, which is why this bit is optional.

Belfiore showed off some smart tricks – for example, he asked Cortana what a friend had been up to, and the assistant produced that friend's page on Facebook. It (sorry, she – Cortana is "female" and named after the AI in the game Halo) can tap into other third-party apps as necessary, for example, Yelp when asked about good restaurants nearby.

There were hiccups in the demo, though, with some voice requests misinterpreted – but that's only to be expected at this stage. Belfiore noted that the system would improve with more users interacting with Cortana, as it learns – and you can also enter queries by text if they're proving troublesome for Cortana's virtual ears.

Belfiore noted: "Cortana isn't just a dry computer returning search results. Just as she has in the game Halo, Windows Phone's Cortana has a bit of personality. But you'll have to talk to her yourself to see what I mean by that. Or... I bet you'll be able to find some videos on the web pretty soon to see what I mean."

Cortana will be arriving with Windows Phone 8.1, but will initially only be available in the States as a beta. The UK and China will get it next, in the second half of 2014, followed by everyone else thereafter in 2015.