TITLE: August 13 -- My Talk on Test-Driven Development
AUTHOR: Eugene Wallingford
DATE: August 17, 2004  2:07 PM
DESC: skepticism about test-driven development
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BODY:

On the last day of SugarLoafPLoP 2004, I gave my
<A HREF="">test-driven development tutorial</A>
as the last event on the main program, just before the closing
ceremony.  I was pretty tired but brought as much energy as I
could to it.  The audience was tired, too, and it showed on their
faces, but most folks were attentive and a couple asked interesting
questions.

One person asked about the role of traditional testing skills, such
as finding equivalence classes on inputs, in TDD.  These skills are
still essential to writing a complete set of tests.
<A HREF="http://www.testing.com/cgi-bin/blog">Brian Marick</A>
and his colleagues in "agile testing" have written a lot about how 
testers work with agile projects.  One of the great values of agile
software development is that most everyone on your team can develop
some level of expertise at writing tests, and can use whatever
knowledge they learn about testing.

Someone in industry asked whether TDD increases the quality of code
but at the cost of longer development times.  I answered that many
believe TDD doesn't increase net development time, because this
approach includes some testing time and because the increase in
code quality means many fewer bugs to fix downstream.  I could not
point to any controlled experiments that confirm this, such as the
ones
<A HREF="http://collaboration.csc.ncsu.edu/laurie/">Laurie Williams</A>
has condcuted on pair programming.  If you know of any such studies,
I would love to
<A HREF="mailto:wallingf@cs.uni.edu">hear from you</A>.
I think this is an area ripe with possibilities.

All in all, folks were skeptical, which is no surprise from an
audience with a serious bent toward traditional software engineering
practice.  TDD and other agile practices are as disorienting to many
folks as finding myself in the Sao Paulo airport was to me.  Perhaps
I helped them to see at least that TDD isn't irresponsible, that it
can be a foundation for sound software development.

This day turned into one like last Sunday -- after a half day of
conference, Rossana Andrade took me and Paulo Masiero on a short
sightseeing and souvenir-shopping trip around Fortaleza.  Then she
and her husband Richard took me to a cool Brazilian pizza place
for dinner, and finally they took me to the airport a few hours
before my 11:10 PM flight to Rio de Janeiro, the first leg
of my journey home.  The day became Saturday with no fanfare, just
a long flight with a layover in Recife to exchange passengers and
arrival in an empty and quite English-free Rio de Janeiro airport.

I must say thanks to my hosts in Brazil, Paulo and Rossana.  They
took wonderful care of me, fed me lots of authentic food, told me
all about their cities and country, chauffered me around, and translated
everything from pizza menus to billboards for me.  Indeed, all the
folks at the conference were wonderful hosts and colleagues.  I can
heartily recommend SugarLoafPLoP to anyone interested in participating
in a patterns conference.
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