OK, Google - who will win the AI wars?

"We're moving from a mobile first to an AI-first world." That was how Google's boss, Sundar Pichai, began a presentation on Tuesday, at which his company unveiled a range of new hardware products.

He believes that the key attraction of both the new Pixel smartphones and the Google Home smart speaker is the company's expertise in artificial intelligence as demonstrated by the Google Assistant.

The search company believes that the vast amount of data it has collected over the years, coupled with its expertise in machine learning, will give it a head start in the coming AI battle.

The company hopes that Google Assistant, a conversational chatbot or virtual PA, will soon be a key feature on all sorts of Android devices, not just those it makes itself.

If Mr Pichai has his way, we will soon be shouting: "OK Google," to get all sorts of information and services.

But on Thursday came news that showed that the biggest player on Android may not be so keen on that idea.

Samsung has announced that it is buying Viv, an artificial intelligence company started by the same people who created the virtual assistant Siri, and then sold it to Apple.

Viv, according to Samsung, is "a unique, open artificial intelligence platform that gives third-party developers the power to use and build conversational assistants and integrate a natural language-based interface into renowned applications and services".

That appears to be a pretty good description of what Google is doing with its AI.

But it sounds as though Samsung may decide that Viv will be a key differentiator on its Galaxy phones - and vast range of household appliances - as it battles to retain its position at the top end of the Android market in competition with the Google Pixel.

And other technology giants are flexing their own AI muscles.

Apple of course has Siri, Microsoft has Cortana, and IBM's Watson has been around for a while and is beginning to make its presence felt in a number of commercial applications.

We also learned on Thursday UK lenders Royal Bank of Scotland and NatWest would use chatbots based on Watson to answer simple customer queries.

Then there is Alexa, the AI at the heart of Amazon's voice-controlled Echo speaker.

Amazon has opened up the Alexa platform to outside developers, and there are already a few Alexa-powered devices out there in the market.

The Echo is in only a few million homes so far, but talking to her (it?) is already proving a compelling example of the promise - and current limitations - of an AI conversational program.

Alexa is pretty good at understanding what you are saying, but not so smart at dealing with follow-up questions.

And this is where Google believes its AI has an edge, saying its Assistant has contextual awareness that allows it to carry on a conversation beyond an initial question.

The company gives as an example the query: "Who is the current British prime minister?"

Try this out with Google, Alexa and Apple's Siri, and all three will produce the answer: "Theresa May".

But follow up with: "How old is she?" and Siri says: "I'm afraid I couldn't find anything on 'How old is she?'" while Alexa tells you she does not understand the question.

But the Google Assistant knows you are referring to Mrs May and comes back with: "Theresa May is 60 years old."

Of course, we are at the very early stages of this revolution, and much may change as each AI learns by doing.

What is more, none of them has yet convinced a significant number of people that conversing with a smart device is something really useful rather than a bit of fun, which you try and then forget.

Both Amazon and Google are betting that this moment comes when we walk through the front door and say: "OK Google, turn on the lights," or: "Alexa, turn up the heat in the hallway."

Now we know that Samsung and perhaps IBM's Watson may also be competing to give us similarly compelling AI experiences.

The mystery is what Apple is up to.

Siri first came to the iPhone five years ago, providing the first experience of a virtual assistant for many.

Since then, while the program has appeared on more Apple devices, and is now on its desktop Macs, it has failed to define this new category.

Where is the Siri speaker or Siri car?

You can be certain that hundreds, perhaps thousands of artificial intelligence experts are at work in Cupertino.

But exactly what ambition Apple has to be a key player in the AI future remains unclear.