[Edu-sig] understanding recursion. . .

[Andre Roberge]

On 2/8/07, Andy Judkis <ajudkis at verizon.net> wrote:
> I teach a "serious computer literacy" course to 10th graders.  The course
> covers some things about how hardware works, how the internet works, what
> operating systems do, etc.  The last part is a 3-4 week intro to Python
> programming.  I've encountered some interesting student behavior and I'm
> curious to know how those of you who are better and more experienced
> teachers would suggest handling it.
>
> Specifically, I've found that many kids seem to have a natural ability to
> use
> recursion, but they don't realize that they're doing it, and they don't
> understand the implications.  [snip].  But they don't have any clue that
> there's
> a call stack involved, or that someday this could get them in trouble.  I
> shudder
> to think about the blank looks that I will get if I try to explain why it
> could be a problem.  So far, I've handled it by pointing out "that's
> recursion,
> you can do that but there's a little more to it and if you're interested,
> ask me or look into it further on your own."  I guess that lets me off the
> hook
> but it doesn't feel quite right.  Other options I can think of are:
> 1) try to explain it and lose most of the class
> 2) just say "I don't allow it, I have a good reason, let me know if you want
> an
> explanation"
> Neither of these feels quite right, either.  These are bright kids but they
> have
> great difficulty understanding things like function parameters and return
> values,
> and I really think recursion is beyond them at this point.
>
> Anybody have any suggestions or similar experiences?

No experience, but you may want to have a look at a little video that
I did a while ago on the topic of recursion:
http://showmedo.com/videos/video?name=rurple2_recursion_andreR&fromSeriesID=15


(Note that I have found since that the tower of Hanoi can be solved
fairly simply using iteration.)

André
>
> Thanks,
> Andy Judkis
> Academy of Allied Health and Science
> Neptune, NJ
>
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