Tricks of the Trade speaks for itself. Though you do kind of wonder what checks they run on people's credentials. How do they know tipsters are the experts they claim to be? The tips seem plausible enough:
ManagerIf you manage a large number of people who are always offering suggestions, insist that feedback be submitted in writing. Blame your faulty memory, if you want to be diplomatic. The bad ideas will be discarded before you hear them, as the employee won't want to go through the effort of writing them out; the good ones will be more complete and better articulated, as the submitted will have to think his idea all the way through before sending it in.
But why should that be any indication of anything?
So I don't endorse any of the practices described, then, obviously, either explicitly or implicitly. Void where prohibited.