Watching representative users attempt real tasks in the product or prototype, without hints, and recording where they hesitate, misread, or fail.
Teams cannot see their own interface clearly: they know where everything is. Five sessions typically surface the majority of serious problems, which is why it is the highest-return research method there is.
We run short moderated sessions on the riskiest flow, ask people to work rather than to give opinions, and report findings as a ranked list of problems with the fix we propose for each.