> The trainers are a group of a few dozen human contractors working in Facebook’s headquarters. These humans, as Marcus explained it, review each of the AI’s responses and decide whether they’re good enough to pass along, or whether they need revising. When the trainers revise, the AI watches and learns: “With every single one of these interactions, that data is fed back into that AI instance that will then use the data to learn how to automate more and more answers or how to get better and better at those things,” Marcus said.

The unfortunate side effect of this is that the training elements won't work on a larger scale. Yes, the underlying AI can, but the training system can't handle thousands of requests per day.

People previewing M post things like this (https://twitter.com/neilkod/status/654442151837831168?ref_sr...) where M does "magical" things like lowering Comcast bills, but this is all stuff that trainers would either have to intervene for or train some system for. The result is that people beg for it to go public, expecting this level of assistance -- even though M won't have nearly the same level of "intelligence" on the backend.

Google Now, Siri, and Cortana could all have the same level of "usefulness" if there was an army of "trainers" on the backend, constantly adding new features for very odd requests, but they wouldn't respond quickly and probably wouldn't be available.