‘View Particles’ option, to observe the transformations and ‘to describe the change by
describing what happens to the ‘particles’. The worksheet guides the students’
observation, for example, in the change from a solid to a liquid, the worksheet
includes the following questions: ‘how are the ‘particles’ arranged in the solid? Are
they completely still?’ and ‘Once the solid has melted what are you left with? How
are the ‘particles’ arranged now? How is this different to their arrangement before?’.
Despite the relatively closed structure of the material presented on the CD-ROM (the
CD-ROM is structured into discrete curriculum units and specific aspects within each
of these units), and the structured worksheet used, the students work with the screen
in different ways.
The Resources of Image and Colour on the Screen
The modal resources of image and colour as they appear on the screen provide the
students with a construction of the entities ‘states of matter’ (solid, liquid and gas)
and the ‘View Particles’ viewing option presents the entity ‘particles’ the
phenomenon to be explored. The ‘Hide Particles’ viewing option displays these
entities from the perspective of the ‘everyday’ world, and the ‘View Particles’ option
displays the scientific view of what is not usually visible - the presence and spatial
arrangement of the ‘particles’ in ‘states of matter’. The visual is presented as
evidence and presents the criterial aspects of what is to be understood; the work of the
student is to ‘read’, that is, to interpret the meaning of these. The task of ‘reading’
these visual signs requires the students to understand what they should attend to and
to select what elements in the visual representation are ‘relevant’ and ‘important’.
Analysis of the students’ engagement with the visual resources of the CD-ROM as
they are displayed on the screen shows the teacher that the students are actively
engaged in this task. It also shows that at some points the visual resources of colour,
texture and shape stand in conflict with the students’ everyday reading of the visual
and that for some students this tension causes some confusion in their reading and
construction of the entities.
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