Squark7700,
The NTSB web site would be a go place to start, then FAA.
As has been said, Sunfish is on the money, in principle the problem is well known and understood, and any pilot who need ADS-B to understand that aircraft might be found around aerodromes would probably be better of fishing.
With all due respect, if "training" was the answer, why do we have any accidents, after all, all pilots have been "trained". How much effort has been put into VFR into IMC propaganda, but it still happens??
One thing that is clearly not understood is the fidelity of the various displays, in reality (have you ever used TCAS 11 on a modern display) it will only tell you there are aircraft around --- at best. Using any of the systems (so far) for traffic separation around an airfield can lead to all sorts of nasty surprises.
Tootle pip!!