Erika Hall presents why purely user-centred design is out-of-date, explains how data-driven design is actually bias-driven design, and debunks the myth of the genius designer working chiefly based on intuition. And offers her own alternative approach:
We need evidence-based design. Because what we are doing first and foremost is designing. It doesn’t matter how much research we do, or what method we use. There is no one right answer. It matters that we have sufficient evidence to support our choices and decisions, however we get that evidence.
From my point of view, the idea of doing "just enough research" proclaimed by Hall is a question of choosing the right methods for the task (often a mix of approaches, and sometimes even just using light versions of them).
And, ultimately, it is not just important what research we do to build up evidence for design, but also how to anchor the knowledge within the design team; ideally the designer-researcher is an integral member of it:
It doesn’t matter how much research you do if the people who have acquired the most knowledge write a report and move on.