[Etoys] simplifying basic category

[Yoshiki Ohshima]

  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.

> 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.

> 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
> > first thing the end-user does after painting/instantiating an object
> > is to pick it up by a mouse and move.
> Seymour Papert invented the "turtle" to get children to steer it indirectly 
> through instructions and not through direct manipulation. Picking up etoys 
> and moving them around helps build hand-eye co-ordination but I believe 
> opening up the etoy and controlling its behavior through scripts is what 
> stimulates deep learning thru body systonic explorations.

  Well, I don't disagree.  But 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.)

> > You have a point, but but for now, I think 
> > current affair is "ok".
> It serves 9-12yrs well. I was trying to reach down to younger kids. The Basic 
> tab in the catalog does not have an etoy. An low cost change would be to add 
> a turtle sketch with pen down and black color nib, so children can start 
> using it to create pen trails right away.

  Actually, we can have a project like that.  We can in fact a lot of
projects to do different tasks and include them.  (Even like
calculator, painting, camera manipulation, etc.)

> >   In future systems, various different notation/representation of
> > vectors should be really nice, too.  What kind of notation would be
> > good for children?
> The arrow serves well to indicate both direction (head) and length (stem).

  That is one.  And how to use it in scripts is something interesting
to think about.

> > > I would have liked to make "pen down false/true" to "pen down/up" but I
> > > am yet to figure out a simple way to get Boolean slots to support
> > > arbitrary strings/symbols instead of just true/false values.
> >
> >   Hmm, you might have to define a new DataType for it...
> 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.

  Thank you!

-- Yoshiki