From observations to descriptions to explanations

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From observations to descriptions to
explanations
Modelling Physical Reality
properties and behaviours of gases

• M.C.Capizzo, L. Lupo and R.M. Sperandeo-Mineo
• Dipartimento di Fisica e Tecnologie Relative,
  Università di Palermo, Italy

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A Course for pre-service teachers preparation
OBJECTIVETo provide student-teachers
with learning environments and computational
tools that will help them to express and reflect
on their concepts and ideas about phenomena and
support their activities concerning
exploration, experimenting and modelling

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Teacher Education Model

• Hands-on learning through activities
  experiments and software
• Training connected with experimentation in
  classroom

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The background
Teachers by themselves have to experience the
kind of learning we think they should provide to
the students
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The Focus
Modelling
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Physics Models as
? Descriptions of phenomena

? Explanations of phenomena

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The approach is developed in several phases

• observing
• analysing pupils spontaneous representations
• experimenting
• modelling

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OBSERVING

• Motion of motes

Heating of compressed gasses
Diffusion of perfume vapours
Thermal expansion of gasses
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EXPERIMENTING (USING MBL)

• Boyles law (P vs V)

A commercial sensor of pressure is used and
volume is registered by the operator. fitting is
performed using EXCEL
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EXPERIMENTING (USING MBL)

• I Gay Lussac law (V vs T)

Sensors of temperature and motion are
used.. Fitting is performed
using Excel.
Experimental data (Pasco system)
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EXPERIMENTING (USING MBL)

• II Gay Lussac Law (P vs T)

Sensors of temperature and pressure are
used.
Experimental data (Pasco system)
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Pupil relevant ideas of atomic-scale models

• Gas molecules maintain some macroscopic
  properties (like thermal expansion, elasticity,
  stiffness,)
• Gas molecules can move, on the contrary of liquid
  and solid molecules
• Gas molecules naturally tend to go away each
  other
• Gas molecules are embedded in some kind of
  substance (sometime called heat)

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MODELLING USING INTERACTIVE PHYSICS

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Introducing the pressure concept from a
microscopic point of view

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Experimenting with models
THE MODEL N particle (hard spheres)M (mass)
mean mass of air moleculesvi (velocities) equal
in modulo and random directionsV (volume of the
container) 10-24 m3
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Video display of the Applet
Speed, number of particles and volume can be
chosen by the user.
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Results of simulations
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Results of simulations
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Main Outcomes

• Computerbased learning environments can
  create contexts in which student-teachers can be
  actively engaged in their learning
  processes
• The different channels conveying information
  allow the using of different learning
  strategies

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Main Outcomes
A new curriculum
from content-based
to process-based
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Main Outcomes
Learning by doing and by reflecting on the
procedures originating the results