Google's Scary Smart New Feature Can Write Email Replies

— -- Google's scary smart new feature can scan your email and offer quick replies to send based on the content.

The smart reply feature will be rolled out to iOS and Android users of the Inbox by Gmail app this week. The feature can analyze the text of an incoming email and then offer three responses users can choose to send as a quick reply.

The system works on a pair of "recurrent neural networks," which are computer systems modeled after the human brain. The more a person uses the feature, the more it will learn about the responses people tend to choose over others, allowing it to offer more tailored suggestions.

One neural network encodes the incoming email and is able to predict possible responses, while the second is able to take that information and craft a grammatically correct reply using language that sounds conversational.

The intent of the app is to make it easier to reply to email on mobile devices by simply tapping an appropriate response, Greg Corrado, a senior research scientist at Google, said in a blog post. He said the feature maintains user privacy and that at no point do humans ever read a private email.

Fine-tuning the feature required some intervention. Corrado said tests of the prototype service tended to offer "I love you" as a response to almost any message.

"It turns out that responses like 'Thanks', 'Sounds good', and 'I love you' are super common -- so the system would lean on them as a safe bet if it was unsure," Corrado said. "Normalizing the likelihood of a candidate reply by some measure of that response's prior probability forced the model to predict responses that were not just highly likely, but also had high affinity to the original message. This made for a less lovey, but far more useful, email assistant."