Good question! I'd say, ultimate task is to achieve both, but what is fully achievable atm is to get the right recipe structure. The idea of "validity" is very hard to evaluate and often has high regional and personal variance, but many teams around the world are working on this problem at the moment!

IBM Chef Watson was quite good at it though, already five years ago. But I haven't found any similar service since it was turned off, what makes it so hard to replicate it?