This is quite an interesting question-
obviously there is still a lot to discover, however, at the end of the day archaeology is a finite resource. Its fairly obvious that there was only ever a fixed number of villas. hillforts, flint scatters, hoards etc... The key question is, do we know what proportion of the original sites survive? Do we know about 95% of all Roman villas or 10% of them - this has some quite interesting consequences as far as heritage management goes.
I am sure I've seen somewhere someone modelling the rate of discovery of specific site types and arguing from the relative increase what proportion of them we've probably found (though I can't remember where this was or the precise methodology).
From: British archaeology discussion list on behalf of Cerridwen Connelly
Sent: Sat 30/01/2010 10:24
To: [log in to unmask]
Subject: Re: [BRITARCH] Is there anything left to fnd?
As this island has been inhabited for millenia, surely one can dig almost
anywhere and find something - not something major, but something:-)