[AnimalMuppet]

Depends. You could then run experiments on team performance in the requirements-to-code phase, separate from the generating-requirements phase. That has its place. And then you could experiment with teams trying to convert informal requirements to formal requirements. That might let you learn some things about the parts that you couldn't learn if you dealt with the whole.

[nradov]

Those are not separate phases, they take place simultaneously. No one does waterfall development anymore.

[mattchamb]

Waterfall development is still pervasive in a lot of industries and companies.

[derekbaker783]

Definitely still out there.