Thirdly, the invisibility, the visual absence, of the bullets at this stage of the design is,
I want to suggest, something that proves to be problematic for the students as they
move from an imagined account of the movement of the balls to the programming of
it within Toon talk.
The students’ gestured overlay with the screen leads them to ‘calculate’ where the
ball will bounce and Emily’s suggestion that they need to place some horizontal
sticks on the planet.
The Entity ‘Bounce’ within Toontalk
The students select the bounce anima-gadget from the Toontalk notebook. (The
bounce anima-gadget is analysed in some detail earlier in the chapter (pages) and is
shown in figure 5.6.) As discussed earlier the entity ‘bounce’ is represented in three
modes, writing, still image, and movement. These three modal representations
provide different resources for the students’ construction of the entity ‘bounce’. The
resources of image, movement, and writing work together to define ‘bouncing’ within
the mathematical paradigm of the system. The two students first look at the bouncing
anima-gadget in the ‘action-state’. They select the two spring behaviours and ‘flip’
them over to look at the representation of bounce in the ‘edit-state’. The multimodal
representation of ‘bounce’ on the anima-gadget specifies (and demonstrates) the
multiple meanings of bounce within the Toontalk, and introduces the notion of
agency. As discussed earlier, the students have not resolved the question of agency
within their earlier design of the game the students’ interaction with the affordances
of the Toontalk now require them to do so.
Attaching Bounce
Once they have read the anima-gadget the students start to program the bounce
behaviour into their game (this is described in Transcript 5.2). First they select and
copy the bounce behaviour (by copying the image of the springs). They then need to
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