Re: [Phys-l] Student Misconceptions

["John Clement" <clement@hal-pc.org>]

Very true.  But besides the fact that research shows how students must
explore Newtonian ideas rather than being lectured at, the usual statement
of NTN is pedagogically wrong.  It always begins with "A body at rest tends
to stay at rest...".  So the students never bother with the second part.
That is obviously just extra stuff.  Reformulating NTN1 with a strong
statement that "Bodies keep moving unless acted on by an external force that
stops them" might be helpful.  And putting it after NTN2 might also be
helpful.

Most of the demos used for NTN1 just show how something that is at rest
tends to stay at rest.  The usual tablecloth pull is one of them.  So
teachers tend to reinforce the wrong thing.  The ILDs do not have a
demonstration of "a body at rest" and instead always have moving bodies.

A good way to see some of the "misconceptions" is to give any of the concept
inventories and then do an item analysis and go over it to see which answers
are given.  Of course the FCI does not have all misconceptions but just the
most common ones.  Or ask similar questions with free response answers.
That is even more enligtening.

John M. Clement
Houston, TX

> A classic mis/pre-conception that everyone must deal with eventually 
> is Aristotelean thinking.
>
> The 'Natural' state of every object it to be at rest and to remain at 
> rest until some outside agent makes it move.
>
> Who can deny the reality of this!!!! It JUST makes SENSE ! ! ! ! !
>
> Every successful intro physics student will learn to recite 
> Newtons First Law -
>
> BUT VERY FEW STUDENTS WILL INTERNALIZE IT ! ! !