option. (She would have seen the ‘View Particles’ version of the transformation of a
gas to a liquid in the first part of the lesson - the representation shows the water
bubbling and the ‘particles’ leaving the ‘top’ of the water to collect on the saucepan
lid (see figure 6.12).) The teacher rephrases the student’s explanation and in doing so
he ‘strips away’ her confusion and ambiguity and he brings into existence the unseen
gas ‘particles’ through his gesture (he raises his finger as a particle from water to the
saucepan lid). Alongside his gesture and talk the teacher uses the image displayed on
the screen to introduce the concept of heating and cooling to explain the
transformation that is shown. Through his use of gesture with the screen, through
talk and image he establishes an empirical frame into which particle theory can be
introduced in the next part of the discussion.
Through the ‘Hide Particles’ viewing option the teacher establishes the connection of
(school) science with the ‘everyday’ empirical world, and the potential of science to
address the questions and problems that people identify through their engagement
with the everyday world. The limited explanatory power of observing the everyday
world is made clear and the need to think beyond what can be seen is established. In
his push to move the students beyond their observations of the everyday the teacher
‘ignores’, he does not pick up on, one student’s example of the everyday (“It is also
condensation as when something outside is cold and something inside is hot and the
coldness and the hotness make.”).The need for explanations to ‘look deeper’ is
realised in the move to the ‘View Particles’ viewing option.
Scientific Explanation of Phenomena
In the next stage of the discussion the teacher switches the viewing option to ‘View
Particles’ and asks the students to describe and explain the transformation from a gas
to a liquid.
The teacher’s spoken distinction between ‘water’ in the pan and ‘liquid’ on the lid of
the pan when working in the ‘Hide Particles’ option is visually realised in the ‘View
253