On Friday 09 April 2010 09:18:55 pm Bert Freudenberg wrote:
On 09.04.2010, at 17:37, K. K. Subramaniam wrote:
I have seen kids drag turnBy:5 tiles multiple times into a script, then try to use the repeat tile before they stumble on the fact that repeat 5 turnBy: 5 is same as turnBy: 25. Understanding angular magnitudes seems to take more 'cooking' time than that for linear magnitudes. Is it because one has to run one's eye over 'empty space' to gage angles? I don't know.
That's more of a mis-use than use, right?
From an adult's PoV, yes. From a kid's PoV, no. That is the way some kids pick up numeracy. See Deborah case study in page 118 of Mindstorms.
When placing elements along a circle, it is easier to use repeat tile than to dup individual tiles.
self heading: 0. 12 timesRepeat: [ self dosomething. self turnBy: 30 ].
or
self heading: 0. 60 timesRepeat: [ self dosomething. self turnBy: 6 ].
This sounds pretty equivalent in spirit to turtle graphics to me (even if you're placing objects and not just marks).
Repetition occurs in many places including graphics. Visual thinkers tend to use graphics heavily but think of weavers, potters, musicians or dancers. See Ron Eglash's research in http://csdt.rpi.edu for its ties into many cultures around the world.
In any case the discussion showed repeat is too useful to remove or even to hide. But moving it to the pen category seems like win-win to me. You still can use it for anything else but it would encourage to use it with pen drawings.
Thanks. Repeat tile has an important role to play in developing numeracy. It helps make the connection between 2+2+2+2 and 2x4.
Subbu