Subject: "The racing car model"
-------------------------------
I am an undergraduate student at the Education Department of
University of Cyprus (for elementary school) and I am having my
Teaching Experience now. This is my first post here.

I have realised the importance of thinking through physical model
analogies and the impact they have on someone's perception since my
high school studies. Now, I want to use these models analogies in a
subject I will teach this week: "refraction of light". I have
remembered of this model I used myself in order to visualize how
light changes speed and/or direction through two different materials:

The model:
A car travels on the tarred road >> first material where speed is
higher
The driver meets gravel passage >> second material where speed is
lower.

If the car goes vertically into the second material then its
direction won't change, but its speed will decrease. If there is an
angle other than 90 degrees, though, the one wheel which is still on
the tarred road will turn faster than the one on the gravel. So, its
direction will inevitably change towards the vertical. Speed will
change too.

Assuming that this is an intuitive knowledge for most kids of age 11-
12 then it is meaningful enough and can be used.

Contribution:
A) The model should not be used to explain the reasons for
which the phenomenon of refraction happens but only in order to
offer a means of visualisation of its results. Refraction should be
handled as an abstract concept because it has no obvious reasons (in
a child's mind-or an adult's mind sometimes) for occurring, even if
they meet it in several everyday life events.
B) The model should be used to provide evidence of a single
ray's refraction. If we use it to explain the way a light beam from
a torch changes its direction, then we wont able to visualise the
way the beam "broadens" after its refraction. Therefore, in such a
case, we can use a model of more than one cars travelling next to
each other. That would be a reliable analogy!

Inconstancies and suggestions:
A ray of light changes speed at the moment it enters the second
material. In the car model, though, at the time both front wheels
are in the gravel, the two rear wheels will still be on the tarred
road. So the speed of the car in those short moments will not be the
same as it will be when all four wheels touch the gravel road.

However, I do not see how this will cause a misconception. Most
probably, an average child will not realize the model's difficulty
unless we mention it. I suggest we don't. It`d cause more confusion.
This brings out a subject I would like to discuss. Dr Taber, in his
article "When the analogy breaks down: modelling the atom on the
solar system", mentions that "pupils can learn as much about the
target by considering the differences as the similarities-as long as
these are made explicit". I would completely agree, only if there
was an addition: There are analogy difficulties that if mentioned
will be counter-productive, such as the one above… I am confident
that some aspects of a model should be left intact, even if they are
gravely conflicting to the cognitive target. Instead, what we should
do is give instructions regarding the model's use for positive
results by explaining why we created it, what its purpose should be
(terms of use!!! ). A model can be created in order to act as an
analogy of the reasons that cause a phenomenon and/or to act as an
analogy of the results of the phenomenon.

Concluding, a model could have a more positive impact for conceptual
development if this proposition is not neglected:
The model's purpose must be explicitly mentioned. ("This is an
everyday life event that you can use in order to visualise HOW light
changes its direction and speed during refraction. It does not show
us WHY, though!") We need to do that, in order to narrow the model's
use in its valid features. Presentation of all the invalid features
that can cause more confusion is now not necessary.

Andreas Georgiou
Andre.Georgiou@...


--- In learning-science-concepts@..., Sue Howarth
<howarthsg@y...> wrote:
> I like this idea very much and will use it next time I teach this
topic - probably with Y8/9.
>
> Simple but effective
>
> Thanks
> Sue
> The Royal High School, Bath
>
> Sue Muswell <sue@m...> wrote:
> I always start the circulation analogy using houses in a suburban
street as
> individual cells with input requirements of post and milk
deliveries and
> output requirements of rubbish removal...they then decide (as
small groups)
> for themselves how to achieve the major supply routes in and
out....in my
> experience, this makes them appreciate that the crucial
requirement of
> circulation is to serve each and every cell - from this, they come
up for
> themselves with the understanding that each capillary is the
equivalent of a
> street with houses (and can see immediately that the most crucial
blood
> vessels are the capillaries). From here they can work out trunk
roads,
> motorways etc as the blood vessels supplying the capillaries - the
one way
> system we impose is how they get round artery vs vein. I developed
this
> after many kids came up with the same misconception that arteries
are the
> most important blood vessels because the blood they carry is
(usually)
> oxygenated, or at the highest pressure and they are seen as 'big'.
This
> method does seem to work in an understanding of the job of the
circ. system.
>
>
>
>
>
> -----Original Message-----
> From: Dr. Keith S. Taber [mailto:kst24@c...]
> Sent: 08 February 2004 12:38
> To: learning-science-concepts@...
> Subject: Re: LSC: Analogy in learning science concepts
>
>
>
> >Target: Blood system
> >Analogue: School
> >
>
> Interesting - I'm not sure if this is intended for the pupils or
the
> science department!
>
> I think the value of these sorts of comparisons comes from the
> exploration of them - having pupils discuss and critique them. If
> Puni is trying this out with classes it could be interesting to
know
> the outcomes: what do the pupils make of it.
>
> Keith
>
> >T : Artery
> >A : Team leader
> >
> >T : Arteriole
> >A : Deputy team leader(or similar)
> >
> >T : Capillaries
> >A : Classroom teacher
> >
> >T : Cells
> >A : Pupils
> >
> >T : Blood( with the 'contents')
> >A : Information(various)
> >
> >T : Heart
> >A : Headteacher(or Senior Management Team)
> >
> >Where analogy breaks down : Blood flows one way: Artery->
> >Arteriole -> capillaries -> Veules -> Vein but information flows
> >from leader to deputy to form tutor to pupils and then feedback
and
> >any other information from pupils to tutor to deputy to leader.
> >
> >If anyone can refine this you are most welcome to make changes.
> >Puni
> >
> >
> >
> >
> >About this list:
> >
> >Purpose: an international forum for discussing aspects of
learning
> >in science, and for circulating news about publications,
projects,
> >etc., related to this theme.
> >
> >Membership: open to teachers at any level, researchers into
learning
> >in science and related fields, and any others interested in the
> >topic.
> >
> >This list gives you the choice of receiving e-mails individually,
or
> >as a single daily digest of all messages circulated that day.
> >
> >homepage:
> ><http://groups.yahoo.com/group/learning-science-
concepts/>http://groups.yah
> oo.com/group/learning-science-concepts/
> >bookmarks to other sites:
> ><http://groups.yahoo.com/group/learning-science-
concepts/links>http://group
> s.yahoo.com/group/learning-science-concepts/links
> >bibliography on learning in science
> ><http://groups.yahoo.com/group/learning-science-
concepts/files/>http://grou
> ps.yahoo.com/group/learning-science-concepts/files/
> >
> >This list is a moderated discussion group (ie postings are vetted
> >for relevance to the group theme).
> >
> >Moderator: Dr. Keith Taber, Faculty of Education, University of
Cambridge.
>
><http://www.educ.cam.ac.uk/staff/taber.html>http://www.educ.cam.ac.u
k/staff
> /taber.html
> >
> >
> >to join an un-moderated general science education discussion
list,
> >please visit:
> ><http://groups.yahoo.com/group/science-
education/>http://groups.yahoo.com/g
> roup/science-education/
> >
> >
> >
> >
> >Yahoo! Groups Links
> >
> >To visit your group on the web, go to:
> ><http://uk.groups.yahoo.com/group/learning-science-
concepts/>http://uk.grou
> ps.yahoo.com/group/learning-science-concepts/
> >
> >To unsubscribe from this group, send an email to:
> ><mailto:learning-science-concepts-unsubscribe@...?
subject=Uns
> ubscribe>learning-science-concepts-unsubscribe@...
> >
> >Your use of Yahoo! Groups is subject to the
> ><http://uk.docs.yahoo.com/info/terms.html>Yahoo! Terms of Service.
>
>
> --
>
>
> Dr. Keith S. Taber
> http://www.educ.cam.ac.uk/staff/taber.html
> University Lecturer in Education
> University of Cambridge Faculty of Education
> Homerton College site
> Hills Road
> Cambridge CB2 2PH
>
>
> to join an electronic discussion list on
> learning in science
> please visit
> http://uk.groups.yahoo.com/group/learning-science-concepts
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
> About this list:
>
> Purpose: an international forum for discussing aspects of learning
in
> science, and for circulating news about publications, projects,
etc.,
> related to this theme.
>
> Membership: open to teachers at any level, researchers into
learning in
> science and related fields, and any others interested in the topic.
>
> This list gives you the choice of receiving e-mails individually,
or as a
> single daily digest of all messages circulated that day.
>
> homepage:
> http://groups.yahoo.com/group/learning-science-concepts/
> bookmarks to other sites:
> http://groups.yahoo.com/group/learning-science-concepts/links
> bibliography on learning in science
> http://groups.yahoo.com/group/learning-science-concepts/files/
>
> This list is a moderated discussion group (ie postings are vetted
for
> relevance to the group theme).
>
> Moderator: Dr. Keith Taber, Faculty of Education, University of
Cambridge.
> http://www.educ.cam.ac.uk/staff/taber.html
>
>
> to join an un-moderated general science education discussion list,
please
> visit:
> http://groups.yahoo.com/group/science-education/
>
>
>
>
>
>
> _____
>
> Yahoo! Groups Links
>
> * To visit your group on the web, go to:
> http://uk.groups.yahoo.com/group/learning-science-concepts/
>
>
> * To unsubscribe from this group, send an email to:
> learning-science-concepts-unsubscribe@...
> <mailto:learning-science-concepts-unsubscribe@...?
subject=Unsu
> bscribe>
>
>
> * Your use of Yahoo! Groups is subject to the Yahoo! Terms
> <http://uk.docs.yahoo.com/info/terms.html> of Service.
>
>
> ______________________________________
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
> About this list:
>
> Purpose: an international forum for discussing aspects of learning
in science, and for circulating news about publications, projects,
etc., related to this theme.
>
> Membership: open to teachers at any level, researchers into
learning in science and related fields, and any others interested in
the topic.
>
> This list gives you the choice of receiving e-mails individually,
or as a single daily digest of all messages circulated that day.
>
> homepage:
> http://groups.yahoo.com/group/learning-science-concepts/
> bookmarks to other sites:
> http://groups.yahoo.com/group/learning-science-concepts/links
> bibliography on learning in science
> http://groups.yahoo.com/group/learning-science-concepts/files/
>
> This list is a moderated discussion group (ie postings are vetted
for relevance to the group theme).
>
> Moderator: Dr. Keith Taber, Faculty of Education, University of
Cambridge.
> http://www.educ.cam.ac.uk/staff/taber.html
>
>
> to join an un-moderated general science education discussion list,
please visit:
> http://groups.yahoo.com/group/science-education/
>
>
>
>
>
> ---------------------------------
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
> http://uk.groups.yahoo.com/group/learning-science-concepts/
>
> To unsubscribe from this group, send an email to:
> learning-science-concepts-unsubscribe@...
>
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.
>
>
>
> Dr.Sue Howarth
> howarthsg@y...
>
> ---------------------------------
> BT Yahoo! Broadband - Free modem offer, sign up online today and
save £80
>
> [Non-text portions of this message have been removed]