In sales skills terminology, "prospecting" often means looking for industrial parks and the like, then doing a quick sweep in order to rapidly scan and flush out potential prospects.
In those sweeps, you speak briefly with the receptionist or secretary to make a quick determination of whether it is worth calling back to see the Decision Maker.
Just what information you are looking for at this early stage of your search for viable leads will vary with your product and the market. The checklist below is a starting point; adapt it to your own uses.
Checklist: The Kinds of Information to be Looking for When Cold Calling