Graph and Directionality
A small graph situated on the right panel of the ‘frame’ beneath the panel of keys
records the effect of their interactivity with the temperature setting and the display in
the ‘screen within the screen’. The graph shows a plotted line with a red ‘X’ marked
on it. The student can ‘raise’ or ‘lower’ the temperature by selecting the circular
indicators of units of temperature, in the form of small buttons, to the left of the
graph. For instance in the case of the change from solid to liquid an ice-cube is
represented as melting, and the ‘X’ moves to the right and up the plotted line to
indicate a rise in temperature. These ‘units of temperature’ are presented visually as a
series of circular dots and offer a visual potential for the comparison between the four
‘states of matter’. The graph introduces ‘directionality’ as a semiotic resource that the
students need in order to be able to read and understand the process of transformation
between ‘states of matter’. A line visually represents an increase in temperature from
the left-bottom of the graph to the top right, and a line represents a decrease from the
top-left to the bottom-right. The link between heat and movement in time is made
visually by the graph; it links the action of the student (clicking) and the display in
the central screen. Finally, the graph draws attention to the key factor in changes in
‘states of matter’, that is temperature, heating and cooling.
The Elements of the Screen: The ‘Screen within the Screen’
The ‘screen within the screen’ (shown in grey-scale in figure 6.7) is an area of
display. The modes of image, colour and movement are combined to display the
transformation from one state of matter to another.
The range of colours used in the central screen stand in stark contrast to the dull
monotone of the ‘frame’. In the central screen colour is used to construct a ‘hyper-
scientific realism’ where how things are in the ‘natural’ everyday world is echoed and
filtered through the lens of ‘scientificness - in which water is blue and ice is pale -
but bluer and paler than in a naturalistic representation. The ‘screen within the screen’
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