Here's another way of looking at the use of the comma (vs semicolon)
in the following sentence:
 
*The use of technology is not an addition to
the curriculum, it is a change in how
curriculum is delivered. *
 
Most handbooks (e.g., 11th edition of Harbrace College Handbook, p. 137)
state that contrasted elements in a sentence can be separated by a
comma.  Most of the examples deal with phrases rather than
independent clauses (e.g., Racing is supposed to be a test of skill,
not a dice game with death), but perhaps that same handbook rule
(maxim?) could be evoked in the case of the above sentence (which
I also like better w/ a semicolon).
 
On a related note, I do think that we have to be careful about
excusing too many sentences having a potential error simply because
we say the writer knows the reader won't be confused--at least
in non-fiction writing or academic writing anyhow.  People aren't
bothered by comma errors simply because they hamper meaning; they
are bothered because the writer suffers in terms of credibility
because the writer appears to not know the rules.  (Hmmm, in that
last sentence, could I have also used the comma instead of the
semicolon?)  So while writers are sometimes going to bend the
rules (as in the technology sentence perhaps), that should probably
be the exception rather than the norm.
 
Sorry, I got a little carried away.
 
larry beason