Alphabet's Google Inc unveiled its answer to Amazon's Alexa virtual assistant along with new messaging and virtual reality products at its annual I/O developer conference on Wednesday, doubling down on artificial intelligence and machine learning as the keys to its future. Google Chief Executive Sundar Pichai introduced Google Assistant, a virtual personal assistant, along with the tabletop speaker appliance Google Home. He also unveiled Allo, a new messaging service that will compete with Facebook's WhatsApp and Messenger products and feature a chatbot powered by the Google Assistant. Allo, like WhatsApp, will also have end-to-end encryption when it is rolled out this summer. Amazon's Echo, a surprise hit that has other tech giants racing to match it, uses a virtual assistant called Alexa, a cloud-based system that controls the Echo speaker and responds to voice-controlled commands by users.

Matrix completion, where we wish to recover a low rank matrix by observing a few entries from it, is a widely studied problem in both theory and practice with wide applications. Most of the provable algorithms so far on this problem have been restricted to the offline setting where they provide an estimate of the unknown matrix using all observations simultaneously. However, in many applications, the online version, where we observe one entry at a time and dynamically update our estimate, is more appealing. While existing algorithms are efficient for the offline setting, they could be highly inefficient for the online setting. In this paper, we propose the first provable, efficient online algorithm for matrix completion. Our algorithm starts from an initial estimate of the matrix and then performs non-convex stochastic gradient descent (SGD). After every observation, it performs a fast update involving only one row of two tall matrices, giving near linear total runtime. Our algorithm can be naturally used in the offline setting as well, where it gives competitive sample complexity and runtime to state of the art algorithms. Our proofs introduce a general framework to show that SGD updates tend to stay away from saddle surfaces and could be of broader interests for other non-convex problems to prove tight rates.

Non-negative matrix factorization models based on a hierarchical Gamma-Poisson structure capture user and item behavior effectively in extremely sparse data sets, making them the ideal choice for collaborative filtering applications. Hierarchical Poisson factorization (HPF) in particular has proved successful for scalable recommendation systems with extreme sparsity. HPF, however, suffers from a tight coupling of sparsity model (absence of a rating) and response model (the value of the rating), which limits the expressiveness of the latter. Here, we introduce hierarchical compound Poisson factorization (HCPF) that has the favorable Gamma-Poisson structure and scalability of HPF to high-dimensional extremely sparse matrices. More importantly, HCPF decouples the sparsity model from the response model, allowing us to choose the most suitable distribution for the response. HCPF can capture binary, non-negative discrete, non-negative continuous, and zero-inflated continuous responses. We compare HCPF with HPF on nine discrete and three continuous data sets and conclude that HCPF captures the relationship between sparsity and response better than HPF.

At its annual I/O conference earlier this month, Google unveiled Google Home, a stubby device equipped with a speaker, a set of microphones, and (via the cloud and a lot of A.I. work) the ability to answer questions and respond to simple commands. When it debuts this fall, Home will also integrate with "smart" thermostats, lights, and other appliances. Want to adjust the temperature or turn off the lights? Google Home is positioned as a rival to Amazon's Echo, a black cylinder that plays music, responds to verbal commands, activates connected devices throughout the home, and, yes, answers questions. Now Apple is reportedly planning its own Home/Echo competitor.

Microsoft on Wednesday announced that it was further "streamlining" its mobile phone business. The firm will lay off more than 1,800 workers, and will focus its phone efforts where they have differentiation, according to Microsoft chief executive Satya Nadella. So while this certainly doesn't mean that Microsoft will ignore smartphones in the future, it certainly sounds like they're not interested in selling Lumia phones -- or any others -- to the average consumer anymore. It may sound a little bonkers to get out of the smartphone market now, when everyone and their mothers are glued to their mobile devices. And this latest move does mean that Microsoft has written down more than the 9.6 billion it spent to acquire Nokia's handset business in 2014.

If a new report is to be believed, Microsoft could debut a pair of streaming devices at E3, both of which could be used to remotely play Xbox One games on another TV within the home. Petri's Brad Sams said he believes that Microsoft will debut a Chromecast-like media stick at E3, optimized for streaming Xbox One games remotely, as well as a Roku-like, stripped-down version of the Xbox One that could play some basic UWP apps from the Windows Store. Sams puts the price of the Chromecast-style device at about 100, and the Roku-like "Xbox TV" at about 150 or so. Microsoft representatives officially declined to comment on rumors and speculation. Why this matters: Without going into specifics, the word I'm hearing is that at least one of these devices probably won't happen.

Apple is reportedly working on its own Siri-based speaker to use in your home that will rival the likes of Amazon Echo and Google Home. The speaker would be powered by Siri and Apple would finally open up the voice assistant to third-party app developers. That means that, similar to Amazon Echo, users could finally use Siri to play music on Spotify or to summon a car with Uber--all from the speaker. Related: WWDC Is June 13-17; Here's What to Expect at the Keynote This would make Siri far more useful than it is at present. There's a huge emphasis being placed on artificial intelligence-powered products, and the market is continually becoming more and more crowded.

Two engineers who helped build Siri, the famous voice assistant built into every iPhone, have claimed to have gone one step better with an all new digital assistant nicknamed Viv. Unlike her predecessor promiscuous Viv flirt will not be locked down to one ecosystem – an advantage which is likely to set it apart from the likes Facebook's M, Microsoft's Cortana, Google Now and Siri itself by Apple. Anyone familiar with existing voice assistants will feel instantly at home with the latest version, which relies on users clicking on a'Viv' button before posing it a question or voice command. Unlike prior iterations however Viv promises to be a whole lot more advanced; as Dag Kittlaus, co-founder and chief executive of Viv demonstrated by querying: "Will it be warmer than 70 degrees Fahrenheit near the Golden Gate Bridge after 5 pm on the day after tomorrow?" For which he received a detailed answer within 10 milliseconds.

Apple is looking to broaden Siri's footprint and usefulness with help from third party app developers and a software development kit. The big question is whether the move will be able to thwart rivals such as Google Assistant and Amazon's Alexa. From connected light bulbs, to plant sensors, to smart locks, and beyond, smart home tech is growing and evolving rapidly. Here you'll find the latest product reviews, news, and how-tos to help you connect your surroundings to the internet in the smartest way possible. The Information is reporting that Apple is opening up Siri to third-party applications.

Welcome to Mossberg, a weekly commentary and reviews column on The Verge and Recode by veteran tech journalist Walt Mossberg, now an Executive Editor at The Verge and Editor at Large of Recode. Fifteen years ago, when the time became ripe for post-PC devices that put a premium on integrating software and hardware, Apple was the best-positioned company to lead the charge -- and it did. The company's vertical integration, its attention to detail and innovation in both software and hardware, and its willingness to make big bets gave it an edge. And it used that edge to reel off its now-familiar string of game-changing products like the iPod, the iPhone, the MacBook Air, and the iPad. Now, the iPod is essentially gone, and the other products are in mature or maturing markets, with either pretty flat or dropping sales.