Honestly I remember the general principal more than any particular techniques!
We could try googling the "reference interview". But basically, just inquire about context: Not just what do you want, but what do you want to use it for, what do you want to do with it. And an iterative back-and-forth process of teasing it out. And basic respect for the person, meeting them on their terms not yours, even if you wouldn't want what they want. Be careful of your assumptions. Ask open-ended questions.
We could try googling the "reference interview". But basically, just inquire about context: Not just what do you want, but what do you want to use it for, what do you want to do with it. And an iterative back-and-forth process of teasing it out. And basic respect for the person, meeting them on their terms not yours, even if you wouldn't want what they want. Be careful of your assumptions. Ask open-ended questions.
When I googled, here's the thing I found that I liked the best: https://opencommons.uconn.edu/cgi/viewcontent.cgi?referer=&h...