LOGO-L> ToonTalk versus MicroWorlds

["Bill Kerr" <kerrb@senet.com.au>]

I've imitated Ken's ToonTalk factorial demonstrations using MicroWorlds. I
haven't put in the scales (to compare the numbers) or bird (to fetch the
answer) at this stage but they could be added if desired.

I think MicroWorlds allows for multiple representations of factorial better
than ToonTalk. I'm putting this up as a hypothesis to be debated / refuted.
ToonTalk only permits a visual representation (which also requires
abstraction -- Dusty erasing numbers in the thought bubble) whereas in
MicroWorlds you can show it by either a high powered recursive procedure
(most elegant but difficult for unsophisticated users) or a visual / text
combination, which seems to me to require less abstraction (and so would be
more accessible for more kids).

MicroWorlds solutions:
1) Most elegant but difficult:

to factorial :no
if :no = 1 [op 1]
op (product :no  factorial :no - 1)
end

2) Visual / text combination (partially imitating Ken's ToonTalk solution):

Create 3 textboxes:
text1: starts at 1, shows number incrementing
text2: shows number whose factorial we want to compute
text3: shows computation of the factorial occuring

Make 2 buttons called reset and factorial

to reset
text2, ct
insert 1 + random 10
text1, ct insert 1
text3, ct insert 1
end

to factorial
if text1 = text2 [text3, pr " insert (se "factorial text2 "= run text3)
stop]
settext1 text1 + 1
text3,  eol
insert char 32
insert "*
insert char 32
insert text1
wait 10
factorial
end

You could add the scales between text1 and text2 by creating a few extra
graphics in the shapes centre and adding some setsh to the code where
required.

Of the 3 solutions available this is the one I'd initially show kids because
it has a visual component and the abstraction is kept to a minimum. In Ken's
solution Dusty has to erase  numbers 4 or 5 times and I think kids would
become confused by this. I might be thinking this just because I know
MicroWorlds better -- I'm not saying the MicroWorlds visual / textual
solution is easy for unsophisticated users but suspect it would be easier.

I think Ken's solution is really interesting but am not convinced that kids
would find this process more accessible or meaningful than the MicroWorlds
solution.

-- Bill Kerr





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