[plt-scheme] 2htdp/image questions

On Thu, Apr 22, 2010 at 4:50 PM, Stephen Bloch <sbloch at adelphi.edu> wrote:
>
> On Apr 22, 2010, at 3:55 PM, Marco Morazan wrote:
>
>> May I suggest that this is not a good idea? It breaks the abstraction
>> that the HtDP languages and universe provide which makes the teaching
>> of programming to beginners possible. The introduction of something
>> like cache-image all of the sudden means that not all images are
>> alike. The _beginner_ must now think about the machinery that renders
>> images in addition to thinking about the problem/game they are working
>> on. IMHO, that is not the way to go.
>
> What part of "I wouldn't teach this in a beginning course" didn't get through? :-)  The "cache-image" proposal is purely an optimization tool, not to be used until you've got a program that produces correct answers but too slowly.  Most of my beginning students will never write an animation that complex, so they'll never need it.
>

Actually, none of it got through clearly. :-( I can only surmise that
you would only use cache-image for students not in a beginning course
or you would use it in courses for advanced students. The question
then is, how many semesters should we expect to keep students using
universe? If only "advanced" students are to use cache-image, should
these students not be moved on to a different "more advanced"
platform?

We only have about 4 years to prepare our undergrads. The use of
universe and HtDP can deliver a good foundation, but students must be
moved on to other platforms. For better or for worse, it is very
likely that they will need exposure to other
platforms/languages/systems to be competitive in the professional
world. My point is that if we (as a community) keep demanding more of
universe et. al, then we run the risk of providing a great education
inside a bubble. So, either way (i.e., use with beginners or not use
with beginners) I am not swayed that such requests are a good idea.

We may disagree and that is what all great dialogue is likely to be
based on. If I am not clear or if I have not understood something
fundamental, please show me where I have erred. Do we really want to
take universe much farther in terms of the rendition of images?
Perhaps it is just me, but I would rather introduce beginning
students, for example, to distributed computing using universe than
use universe to deepen understanding about image renditions and
thinking about the machine. I guess it depends on what we see as the
goal for universe/HtDP. Food for thought.....

-- 

Cheers,

Marco