I agree with Nero. Forget about Kirkpatrick. It does not fit your situation as you have defined it - which is pretty vague.

What would you suggest? Kirkpatrick has just been around for such a long time and seems to be used widely...have also read about the Holton evaluation model, but don't know if people use it. Seems to have theory to it, but not practice (or not yet developed)...

I would suggest you first figure out exactly what kind of data you're trying to gather and of that, what is valid and reasonable. How can one select an instrument if one doesn't even know what one is trying to gather? In my opinion, this is another classic case of selecting a tool, method, solution, etc. before really knowing what it is one really needs.

More specifically, I am looking to see if program theory (for the volunteer program) and outcomes match. Any other thought based on any type of evaluation model that has been tested and tried?

Mizo,

Who would be providing the feedback?

Would it be the program graduates, the people the graduates work with, or both?