Re: [Phys-l] Student Misconceptions

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

According to Priscilla Laws tests on the conceptions increase up to two
weeks after IE instruction.  But memorized information decreases over two
weeks after instruction.  It takes time to reorganize the brain.  Shayer &
Adey noticed something similar to this in their first testing of Thinking
Science.  The tests went down for a while, before finally rising at the end.
And TS had a large delayed positive effect on standardized test in the UK.

So a delayed test is probably a much better indicator of learning.

John M. Clement
Houston, TX


> I would not just calll them preconceptions -- I'd call them 
> post-conceptions too, stubborn buggers!  
>
> For example:  AFTER we have studied free-fall, AFTER a test 
> which most students did well on, and after we have learned to 
> analyze basic postion and velocity graphs, I tell my studetns 
> that we are going to drop a picket fence past a photogate and 
> the computer will graph the velocity.  But we are going to do 
> this 3 times, hanging 100, then 200 and then 300 grams from 
> the picket fence.  I ask these students to predict what the 
> data will look like.  Most common prediction (by far):  three 
> lines, of three slopes: low, medium and high.  Then I make 
> them predict the slope of the lines.  Most pick three random 
> but ascending numbers.  Then I let them compare their 
> answers.  I will say that though only maybe 1 in 10 students 
> has picked three identically sloped lines, once the others 
> see that prediction, it is quickly recognized as most likely. 
>  Then they do the experiment and of course all three lines 
> have nearly the same slope, all in the 9.8 neighborhod.  
>
> The point is that most of my students believe that heavier 
> objects fall faster even after they have "learned" otherwise. 
>  And if I wait 3 weeks and then ask again, I bet some of them 
> still believe it.  Stubborn indeed.