[A transcript of the SIGCSE 2008 conference: Table of Contents]
I ended the first day by attending a two-man "panel" of
NSF's inaugural
CISE Distinguished Educational Fellows,
Owen Astrachan
and
Peter Denning.
The CDEF program gives these two an opportunity to work
on wild ideas having the potential "to transform
undergraduate computing education on a national scale,
to meet the challenges and opportunities of a world where
computing is essential to U.S. leadership and economic
competitiveness across all sectors of society." A
second-order effect of these fellowships is to have a
soapbox (Denning) or bully pulpit (Astrachan) to push
their ideas out into the world and, more important, to
encourage the rest of the community to think about how
to transform computing education, whether on the CDEF
projects or on their own.
Owen went first. He opened by saying that the CDEF call
for proposals had asked for "untested ideas", and if he
couldn't propose one of those, well... I've mentioned his
Problem Based Learning
learning project here before, as part of an ongoing
discussion of teaching that is built around real problems,
projects, and meaningful context. Owen's talk described
some of the motivation for his project and the perceived
benefits. I'll try to report his talk faithfully, but
I suspect that some of my own thoughts will creep in.
When we talk to the world as we talk among ourselves --
about choices of programming language, IDE, operating
systems, ... -- we tell the world that tools are
the coin of our realm. When an engineer comes to us and
asks for a course using MATLAB, we may be 100% technically
correct to respond "Python is better than MATLAB. Here's
why..." -- but we send the wrong message, a damaging message,
which makes it the wrong response.
We can engage those folks better if we talk to them about
the problems they need help solving. In many ways, that
is how computing got its start, and it is time for us
again to look outside our discipline for problems to
solve, ideas to explore, and motivation to advance the
discipline. Increasingly, outside our discipline may well
be the place for us to look for learners, as fewer
folks express interest in computing for computing's sake
and as more non-computing look for ways to integrate
computing into their own work. (Like
scientists
and even
artists.)
That is one motivation for the PBL project. Another was
the school Owen's children attend, where all learning is
project-based. Students work on "real" problems that
interest them, accumulating knowledge, skill, and experience
as they work on increasingly challenging and open-ended
projects. Problems have also driven certain kinds of
scientific professional education at the university level
for many decades.
For the first time in any of his talks I've seen, Owen
took some time to distinguish problem-based learning
from project-based learning. I didn't catch most
of the specific differences, but Owen pointed us all to
the book
Facilitating Problem-Based Learning
by Maggi Savin-Baden for its discussion of the differences.
This is, of course, of great interest to me, as I have been
thinking a lot in the last year or more about the role
project-based courses
can play in undergraduate CS. Now I know where to look
for more to think about.
As a part of
eating his own dog food,
Owen is trying to ratchet up the levelof dialogue in his
own courses this year by developing assignments that are
based on problems, not implementation techniques. One
concrete manifestation of this change is shorter write-ups
for assignments, which lay out only the problem to be
solved and not so much of his own thinking about how
students should think about the problem. He likened this
to giving his students a life jacket, not a straitjacket.
I struggle occasionally with a desire to tie my students'
thinking up with my own, and so wish him well.
Where do we find problems for our CS majors to work on?
Drawing explicitly from other disciplines is one fruitful
way, and it helps CS students see how computing matters
in the world. We can also draw from applications that
young people see and use everyday, which has the potential
to reach an even broader audience and requires less
"backstory". This is something the elementary patterns
folks have worked on at ChiliPLoP in recent years, for
example
2005.
(Ironically, I am typing this in my room at the
Spirit in the Desert Retreat Center,
as I prepare for ChiliPLoP 2008 to begin in the morning.
Outside my window is no longer rainy Portland but a
remarkably cold Arizona desert.)
Owen said we only need to be alert to the possibilities.
Take a look at
TinyURL
-- there are several projects and days of lecture there.
Google the phrase
dodger ball;
why do we get those results? You can talk about a lot
of computer science just by trying to reach an answer.
After telling us more about his NSF-funded project, Owen
closed with some uplifting words. He hopes to build a
community around the ideas of problem-based learning
that will benefit from the energy and efforts of us all.
Optimism is essential. Revolutionizing how we teach
computing, and how others see computing, is a daunting
task, but we can only solve problems if we try.
Denning took the stage next. He has long been driven
by an interest in the
great principles of computing,
both as a way to understand our discipline better and
as a way to communicate our discipline to others more
effectively. His CDEF project focuses on the different
"voices" of computing, the different ways that the world
hear people in our discipline speak. In many ways,
they correspond to the different hats that computing
people wear in their professional lives -- or perhaps
our different personalities in a collective dissociative
identity disorder.
Denning identifies seven voices of computing: the
programmer, the computational thinker, the user, the
mathematician, the engineer, the scientist, and the
"catalog". That last one was a mystery to us all until
he explained it, when it became our greatest fear...
The catalog voice speaks to students and outsiders in
terms of the typical university course descriptions.
These descriptions partition our discipline into artificial
little chunks of wholly uninteresting text.
What makes these voices authentic? Denning answered the
question in terms of concepts and practices. To set up
his answer, he discussed three levels in the development
of a person's understanding of a technology, from mystical
("it works") to operational (concrete models) to formal
(abstractions). Our courses often present formal
abstractions of an idea before students have had a chance
to develop solid concrete models yet. We often speak in
terms of formal abstraction to our colleagues from other
disciplines. We would be more effective if instead we
worked on their problems with them and helped them create
concrete results that they can see and appreciate.
One advantage of this is that the computing folks are
speaking the language of the problem, rather than the
abstract language of algorithms and theory. Another
is that it grounds the conversation in practices, rather
than concepts. Academics like concepts, because they
are clean and orderly, more than practices, which are
messy and often admit no clean description. Denning
asserts that voices are more authentic when grounded in
practices, and that computing hurts itself whenever it
grounds its speech in concepts.
His project also aims to create a community of people
around his ideas. He mentioned something like a
"Rebooting Computing" summit that will bring together
folks interested in his CDEF vision and, more broadly,
in inspiring a return to the magic and beauty of
computing. Let's see what happens.
I heard several common threads running through Astrachan's
and Denning's presentations. One is that we need to be
more careful about how we talk about our discipline.
Early on, Denning's said that we should talk about what
computing is and how we do it, and not how we
think about things. We academics may care about
that, but no one else does. Later, Owen said that we
should talk about computational doing, not
computational thinking. These both relate to the
intersection of their projects, where solving real
problems in practice is the focus.
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