I find myself wanting a little more detail on the “Interview-based usability test” technique.

Spending time in advance to formulate tasks with the participant, and then in that same session conduct a usability test would seem really time consuming to me. Even with pre-defined tasks, I find usability studies are typically about an hour or 1.5 hours long. A participant usually gets pretty exhausted past 1.5 hours. I suppose you could limit to two tasks, but that probably wouldn’t suffice for more complex “enterprise” type products

Do you have a recommendation on how to keep a session like that contained? Also, how do you report your findings at the end? If you test 6 users, but they all have vastly different tasks, it’s difficult to quantify in aggregate across all of your participants (despite collecting a good deal of handy qualitative feedback / observations).

Any pointers elaborating on that technique would be much appreciated!

Cheers,
Etan