[Note: You had hijacked a previous thread. I moved your post out of that thread so that it can get replies for you. I also removed your request for emails - we want people to reply here, rather than just in private emails. Joe]
My suggestion is always to understand how the app or system is used in the real world before considering how one would test it-- if you aren't familiar with the industry, then I agree, this would be a bit rough.
Are you referring to the technical aspects of testing an ATM machine, or the bigger picture?
This does sound like a pretty common interview question [img]/images/graemlins/wink.gif[/img]