Generative vs evaluative - and the method menu

Method fit is a two-question test: are you trying to learn what to build or check something you've already built? And do you need what people say or what they do?

Get the first question wrong and every downstream choice is off. Generative research expands the space of what you might build. Evaluative research narrows or validates something already on the table. Bringing a usability test to a generative question gives you a polished answer to a question nobody needed.