TITLE: ChiliPLoP 2007 Redux
AUTHOR: Eugene Wallingford
DATE: February 21, 2007  5:50 PM
DESC: 
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BODY:
Our working group had its most productive ChiliPLoP in recent
memory this year.  The work we did isn't ready for public
consumption yet, so I can't post a link just yet, but I am
hopeful that we will be able to share our results with
interested educators soon enough.  For now, a summary.

This year, we made substantial progress toward producing a
well-documented resource for instructors who want to teach
Java and OOP.  As our working paper begins:

<BLOCKQUOTE><EM>
The following set of exercises builds up a simple application
over a number of iterations.  The purpose is to demonstrate,
in a small program, most of the key features of object-oriented
programming in Java within a period of two to three weeks.  The
course can then delve more deeply into each of the topics introduced,
in whatever order the instructor deems appropriate.
</EM></BLOCKQUOTE>

An instructor can use this example to lay a thin but complete
foundation in object-oriented Java for an intro course within the
first few weeks of the semester.  By introducing many different
ideas in a simple way early, the later elements of the course
can be ordered at the instructor's discretion.  So many other
approaches to teaching CS 1 create strict dependencies between
topics and language constructs, which limits the instructor's
approach over the course of the whole semester.  The result is
that most instructors won't adopt a new approach, because they
either cannot or do not want to be tied down for the whole
semester.   We hope that our example enables instructors to do
OO early while freeing them to build the rest of their course
in a way that fits their style, their strengths and interests,
and their institution's curriculum.

Our longer-term goal is that this resource serve as a good example
for ourselves and for others who would like to document teaching
modules and share them with others.  By reducing external
dependencies to a minimum, such modules should assist instructors
in assembling courses that use good exercises, code, and OO
programming practice.

... but where are the patterns?  Isn't a
<A HREF="http://www.hillside.net/patterns/">
   PLoP conference</A>
about patterns?  Yes, indeed, and that is one reason that I'm more
excited about the work we did this week than I have been in a while.
By starting with a very simple little exercise, growing progressively
into an interesting simulation via short, simple steps, we have
assembled both a paradigmatic OO CS 1 program <STRONG>and</STRONG>
the sequence of changes necessary to grow it.  To me, this is an
essential step in identifying the pattern language that generates
the program.  I may be a bit premature, but I feel as if we are
very close to having documented a pattern sequence in the
<A HREF="http://www.patternlanguage.com/">
   Alexandrian sense</A>.
Such a pattern sequence is an essential part of a pattern-oriented
approach to design, and one that only a few people -- Neil Harrison
and
<A HREF="http://users.rcn.com/jcoplien/">
   Jim Coplien</A>
-- have written much about.  And, like Alexander's idea of pattern
diagnosis, pattern sequences will, I think, play a valuable role in
<A HREF="http://www.cs.uni.edu/~wallingf/patterns/elementary/conferences/oopsla98_workshop_rtp.html">
 how we teach pattern-directed design</A>.
My self-assigned task is to explore this extension of our ChiliPLoP
work while the group works on filling in some details and completing
our public presentation.

One interesting socio-technical experiment we ran this week was
to write collaboratively using a
<A HREF="http://docs.google.com">
   Google doc</A>.
I'm still not much a fan of browser-based apps, especially word
processors, but this worked out reasonably well for us.  It was
fast, performed autosaves in small increments, and did a great
job handling the few edit conflicts we caused in two-plus days.
We'll probably continue to work in this doc for a few more weeks,
before we consider migrating the document to a web page that we
can edit and style directly.

Two weeks from today, the whole crew of us will be off to SIGCSE
2007, which is an unusual opportunity for us to follow up our
ChiliPLoP and hold ourselves accountable for not losing momentum.
Of course, two weeks back home
<A HREF="http://www.cs.uni.edu/~wallingf/blog/archives/monthly/2007-02.html#e2007-02-18T16_25_17.htm">
   like this</A>
would certainly wipe my mind clear of any personal momentum I
have built up, so I will need to be on guard!
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