TITLE: No, Really, Why?
AUTHOR: Eugene Wallingford
DATE: September 24, 2004  1:56 PM
DESC: second thoughts on why not TDD?
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BODY:
My
<A HREF="http://www.cs.uni.edu/~wallingf/blog/archives/monthly/2004-09.html#e2004-09-24T11_12_05.htm">
   message earlier today</A>
was just a riff on the quote I began with.  I was in an
especially "why not?" kind of mood.  As I walked to lunch,
though, I knew that many of my students, including many of
the better ones, would be unfazed by my rhapsody.  They
have plenty of reasons for resisting the switch to TDD.
And those reasons seem quite powerful to them.  Let's
consider two.

<I>It takes too much time.</I>  Students don't always have the
luxury of time when designing, implementing, and debugging an
assignment.  The program is due in a week or two, and so they
spend most of their time working just to write a program that
works.  Evidence such as "TDD takes 15% longer and results in
30% fewer defects" doesn't provide much motivation to do TDD
when students don't think they *have* 15% more time.  They'll
take their chances with working on what really matters, which
is the program.  Requiring students to submit their tests and
then grading them, too, may motivate them, but I'd like to
hear from folks who have tried that before deciding that it
really works -- or whether students just view it as an extra
burden, an 'unfunded mandate' from the instructor.

<I>Old habits die hard, if at all.</I>  Even if convinced of the
value of TDD, many people find the change in habit to be a
difficult obstacle to surmount.  Changing habits takes discipline,
support, and time.  Instructors aren't usually with students
enough at the times they program to help with the discipline,
so our ability to provide support is compromised.  When the
pressure is on, or when faced with a challenging tasks, people
tend to fall back on what they know best, what feels comfortable
-- even if they aren't confident that the old ways will work!
As an instructor, I find it most frustrating to watch students
fall back on practices they know will fail, but I realize that
this is simply human nature.  Without changing the students'
environment more radically, effecting certain changes of habit
will be a hit-or-miss affair.

Maybe this comes down to the fact that we who teach need to change
the way <I>we</I> do things.  Give assignments over longer periods,
allowing more time for reflection.  This sounds good, but ...
What about the stuff we can't do because we now don't have time?
It's a commonplace that students may be better off learning less
content better, with more growing of the mind, but making that
change is a difficult obstacle for teachers to surmount.

In the end, I wonder how much effect such a change would have
anyway.  Would all the students' newly freed time be sucked up
by their other courses, their jobs, and their ordinary lives?

Ultimately, this all comes down to motivation, and the best
motivation comes from inside the learner.  Drawing that desire
out is a task for which instructors aren't usually well-prepared.
We can learn to do a better job of motivating students, but
that takes work on our end.  And wouldn't we rather just lecture?
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