QUOTE(Invidia @ Apr 2 2012, 10:08 AM)

You definitely wouldn't perform each section as if to say "this is the exposition, and now this is the development etc" because you don't want to fragment the music- yes it's sonata form but you want a continuous flow.
I think it's all about the subtleties and what you as a performer want to alert the listener to. Something as simple as making core motifs a little more incisive can make a big difference; a listener may not know all of the jargon, but they will know in the exposition that certain things keep coming back and that in the development they recognise bits but they have changed.
Depending on what sonata you are working on, sometimes there is space for a little breath between one or two sections which can flag up an end of one thing and a beginning of another.
I would avoid playing repeats the same; in any good sonata recording there are subtle changes of shading if something is repeated. I think this is relevant to the question because you're saying that your listener would be aware of repeated material so you are changing your interpretation to avoid boredom.
Listeners from your professionals to your tone deaf have an incredibly astute perception of rhythm. I would argue one of the most important things to be throwing melody and harmony out of the window for a couple of practise sessions and looking at the rhythmic structure of the piece- rhythm of melodic motifs, rhythm of melodic motifs in the accompaniment/other voice, does this change in the development? are there any rhythmic patterns that go right through the movement without changing (continuity is just as important as establishing structural difference).
Those are my thoughts- I don't know much about sonatas outside the theory of them to be honest. You're probably doing it all anyway but sometimes when it's thrown at us as an exam question, all knowledge of what we've been doing goes out of the window.
Thanks for your insight, I'm varying parts but not to the depth that you are suggesting. So I'm going to have a more in depth look at the sonta (mauro Guiliani sonata in C) I can't play it as fast as the proffesionals so I'm going to add more musicality. Plus I'm not a academic person so these questions feel abit alien.