(The assignment allowed for 2 points for three interviews, up to four points total, for one or two students -- I wanted the students to be safe, so per student points did not fall if they were a pair. There was no requirement that they give any money.)
I said that they needed to ask panhandlers name, age, where they were from, how much they made and their plans for the future.
My students did an amazing job, and many of them wrote side notes on their feelings about what they learned; this assignment taught us all a lot.
Sungmin and Hak Ryul did a particularly good job. I recommend that you read their full report [doc].
Seriously, read it (four pages). You'll learn something.
Bottom Line: You really don't know much about people until you talk to them, to learn their version of the story. (Even then, you have to remember that it's their version.)