Terry writes -

In as much as the human computer interface* is important to the student's experience of the computer, I think we still are. I agree that the textual interface is critical to something like programming, where logic and a linear progression of steps are fundamental to the subject. But if you were teaching 2- or 3-D concepts, the ability to simply point and select objects, and express your intent in a visual-tactile mode is just essential.

It shouldn't surprise you that I want to strongly disagree with this. Or strongly disagree with my perhaps incorrect interpretation of what you are saying, which is more likely as these things go. PyGeo's design is deliberate, in essentially limiting one to "logic and a linear progression of steps" in creating 3d structures, i.e. in teaching 3d concepts. In other words, it is deliberately insisting on deliberation. True, once created, the fact that the structures can be manipulated interactively - but holding the deliberately established relationships invariant - is also essential to it, as it is with any dynamic geemetry app. On second thought, I don't fully disagree, in that the place, at the moment, where I am probably most dissatified with PyGeo is exactly the limitations of the interface for picking and moving points in 3d space. The limitation there is firstly my own. I've not got my mind around the trackball concept and the mouse - partly, I think becuase it seems to have enough of its own limitations that I can't get fully motivated to make the effort. A better interface would be wonderful. I offically back off ;. Art