is related to a series of keys that indicate the central areas for the investigation of the
topic within the CD-ROM. These are displayed as a set of rectangular ‘buttons’ in a
vertical list. When a button is selected it is highlighted in yellow, as a sign of its
active state. Each of these ‘buttons’ relies on the mode of writing and acts as a written
‘caption’- a kind of ‘label’, for the entities visually displayed in the central ‘screen
within the screen’.
The ‘Hide Particles’ and ‘View Particles’ Viewing Option
A ‘Hide Particles’ or ‘View Particles’ button is displayed on the right-hand panel.
This key is the means by which students can switch the displayed appearance of the
sequence in the central screen (each display is described in more detail later in the
chapter). The viewing option ‘Hide Particles’ displays an ‘everyday’ view of the
transformation of ‘states of matter’. Here the focus is on ‘what is’ and ‘how things
are’ in the world of the everyday, focusing on the change in shape, ‘texture’ and
movement from one state to another, for example, from a solid to a liquid. By
contrast, the option ‘View Particles’ displays a view beyond and beneath the
everyday: a scientific view, in which the focus is on explanation ‘How things actually
are’. The multimodal representation of the ‘Particles’, their visual presence and in
particular their movement serves to display the ‘motivation’ for the changes that can
be seen in the shape and the texture of the material. They also enable the students to
move between the two accounts of ‘states of matter’ (solid, liquid, and gas), that is,
the everyday and the scientific.
The facilities of the CD-ROM enable the students to ‘Pause’ the moving
representations, and to observe the changes in the transformation between the states.
The potential to move between the two representations of the states and the specific
states produces a tension between the two views in which each representation
‘visually explains the other’ to produce a plausible account of the phenomena.
219