Modularity and reuse

Modular content can be reused most effectively when
a) it has such fine granularity (e.g. a sentence), that it blends in
well with the other content.
b) the re-user understands it thoroughly enough, including the context
in which it was written (by this point, they might as well have written
it themselves).
c) the re-user knows it exists

From my point of view, the content management paradigm is a solution
looking for a problem, pushed by vendors of database-driven systems. I
can see the case for reusing graphics and multimedia exercises (fed from
a repository), but the current craze about reusing textual content (and
about making one-page SCOs so that they can be put into a repository)
results in "ransom notes"; especially when the database system is
responsible for assembling the reused content.

What I do see that works well is when someone reuses someone else's
document or chapter when the necessary changes are small. For example,
most law offices don't rewrite every document from scratch. It makes
sense to re-use documents like wills, contracts, etc., that have evolved
over many years. Still, reuse requires that the re-user fully
understand the implications and subtleties of the document being reused;
otherwise, they may commit the customers to terms and conditions that
are undesirable.

What about reuse by the learner - e.g. they come back to it multiple
times or they view it on their browser, PDA, printed paper, etc.?