[plt-scheme] Re: HTDP - evidently not for everyone.

From: Stephen Bloch (sbloch at adelphi.edu)
Date: Fri Feb 12 11:58:30 EST 2010

> I wrote:
>> My textbook makes a point of giving, for each topic, a "worked  
>> exercise" followed immediately by an unworked exercise that's  
>> almost identical, then one that's a little more different, and so on.

and Matthias replied:

> .. which of course is the antithesis of HtDP. So perhaps you're  
> just trying to prove the subject line :-)

Perhaps.  The point was that if I assign an exercise that's almost  
identical to the one I just did FOR the students (complete with  
design recipe), it helps push them over the passive-to-active hump,  
and then they can start applying the design recipe to gradually more  
and more unfamiliar problems.

Often the "exercise that's almost identical" really differs only in  
replacing one literal by another, containing no new concepts at all.   
I've done "count-over-10" for you; now you do "count-over-20", then  
"count-under-20", then "count-even", then "count-cats", then ...

Sometimes, before I even assign an almost-identical exercise, I'll  
ask students to type in the worked exercise verbatim and make sure it  
works for them.  This doesn't require any actual thinking, but it  
gets them doing something with their own fingers rather than just  
watching and listening, and it identifies any mechanical difficulties  
that students are having with DrScheme (or, God forbid, typos in the  

Actually, I don't see how this is inconsistent with HtDP at all :-)

Stephen Bloch
sbloch at adelphi.edu

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