[Etoys] simplifying basic category

subbukk subbukk at gmail.com
Sat Nov 3 13:47:57 EDT 2007

On Saturday 03 November 2007 4:11 am, Yoshiki Ohshima wrote:
>   Subbu,
> > I am not so sure. Three reasons. Firstly, heading counter is not really
> > needed to "play turtle". 5-7yr olds are quite sensitive to small changes
> > and the changing counters could divert their attention from the etoy.
>   You could drop the bi-directional connection idea for the younger
> learners, yes.  But can end up with something a bit different from
> Etoys.
Once a young learner gets used to the idea of control and starts exploring 
other properties, (s)he will encounter it in geometry. heading is not gone, 
it continues to be in geometry category. So how does it change Etoys?

> > Secondly,
> > heading is based on an absolute reference. Body systonic movements are
> > always relative and there is no fixed "north". Older children who
> > understand absolute measures will intuitively reach out into geometry for
> > the heading counter.
>   However, the turtle does move and rotate on screen currently.
> Unless we can really fix the turtle on screen and use the turtle local
> coordinate system throughout and move the rest of the world (i.e.,
> "turn left" makes the world rotates right, and "forward" means the
> world slides backward).  If so, I could agree with the idea to take
> out the global coordinate values.
I am not suggesting that we change the co-ord system. Currently Etoys 101 
introduces both turtle and cartesian co-ords (which was fine for its initial 
test group of 9-12yr olds). All I am suggesting is to keep only simple turtle 
co-ords for Etoys 101 (5-7 yr olds) and bring in cartesian co-ords (geometry) 
in Etoys 201. Recall the case of Deborah (Mindstorms, page 118).

> > Thirdly, "north" is forward only for top-view (as in children
> > playing with toys on the floor). When sketching on screen, children tend
> > to draw side-view or front-view and then the "forward" movement is
> > disconcerting (cf. Alan the mouse in Squeaky tales video).
>   Yes, that is a brilliant part of Logo.  But I think this is a weak
> argument to remove heading from basic.
The observation is from watching 6-9yr olds (not all of whom know English) 
using Squeak. I am having way too much fun with kids in this age group :-). 
Getting a sketch to draw a triangle, square etc. doesn't need heading. It is 
more of a distraction in basic category. heading makes sense only to kids old 
enough to understand compass points and negative numbers.

> a typical Etoys session begins with
> drawing a painting, so how to merge the idea you described into that
> flow is not trivial (like removing heading and x, y would not.)
It still does. Kids still get to sketch first and script a circle. Young kids 
continue their fun with shapes and trails with their car while older compass 
aware kids can build wheels and control the car with that. My suggestion is 
to remove these only from the basic category. The cartesian co-ords will be 
available in geometry.

> > That wouldn't be extensible. I am trying to get Boolean slots to display
> > any two names - up/down, inside/outside, dead/alive etc. so that the tile
> > names reflect real world behaviors and don't look contrived.
>   Yes.  DataType and friends is the classes to modify to provide that.
Thanks for the pointer.


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