Greetings,
Prior to learning Excel VBA most of my programming was in C and
wasn't concerned with GUI interfaces (I am a mathematician who writes
programs more as an avocation in order to explore various
probabilistic and combinatorial problems). I've turned to VBA because
I can get functioning code quicker and because I find it fun to create
animated charts to illustrate the algorithms. Even though my programs
are for my own consumption, I have a perfectionistic streak and want
them to have at least a semi-professional look and feel. Towards this
end I have been gradually increasing my use of user forms and event
handlers. Mostly I have been adding these *after* the program is
functioning. As a result of this, my GUI elements seem to have an
ad-hoc feel about them since they really are a pretty thin layer over
the "real" code.

I am currently reading the book "Excel VBA - Professional
Projects" by Duane Birnbaum and have been struck by the way that he
tends to (after clearly specifying the project and outlining the
solution) create user forms and custom tool bars *before* writing the
bulk of the code. Steve Roman's book seems similar. So my long-winded
question is: which seems to work better, starting with an interface
and then gradually fleshing out the code behind it, or coding the core
logic and then creating a graphical front end for it? Is there some
sort of consensus amoung developers or is this just a matter of taste?

Thank you for your time.

-John Coleman