Re: [Phys-l] Understanding the physics lab

[John Denker <jsd@av8n.com>]

On 01/03/2010 09:58 AM, Arts, Robert W. wrote:
> ... many
> cookbook labs take only a fraction of that time; after which the
> students head off on their own to complete a laboratory report or
> notebook.  

Yeah.

> I'd like to change that format. 

Good!

> ... My
> main interest is their ability to not only connect the experiment to
> the concepts but to be able to relate their own data to the
> theory.....

Good!

> What I'd like to accomplish is that they remain in the laboratory for
> the entire three-hour block of time but at the end have produced
> suitable laboratory report that can be handed in as they leave. 

That would be a step in the right direction, but here's
another thing to think about:

In the real world, good experiment design means taking some
data, analyzing it, and then taking more data, et cetera,
iteratively.  The point is that by iterating, you get smarter
about how to take the data.  If there are misconceptions 
about the procedure, or avoidable mistakes, you have a
chance to do better on the next iteration.

In the real world, theory guides experimentation *and*
vice versa.

Real engineers build prototypes and pilot plants before
committing to full-scale production.

Real life isn't about doing everything perfectly the first
time.  Good strategy is to never allow yourself to be put
into a situation where it is impossible to recover from a
mistake.  This applies double for students, who pretty 
much by definition are not experts, and can be expected
to make mistakes.  It is horrifying to see "cookbook labs" 
that require taking all of the data and then (at home or 
otherwise) analyzing it all later.

=======

Understanding is the goal.  Learning good habits is the goal.
Taking all the data before doing any analysis is not a good
habit.

Being able to turn in the final report at the end of the
period is not the goal.  There should be homework.  Using
class time to do things that could equally well be done
at home is not an optimal use of resources.

If necessary, you could divide the lab period in half, as
follows:  In the second half of the period, do the 
preliminary observations for one topic.  Then they go 
home and do the preliminary analysis.  During the next 
period, they do the follow-up observations on the first
topic, and then the preliminary observations on a second
topic.  

=============

Something else to think about:  This thread implicitly (and
now explicitly :-) calls into question the wisdom of having
3-hour lab sessions.  It is better in many ways, including
being more like the real world, if students can observe for
an hour or so and then go off and think about it -- leaving 
the apparatus set up -- and then come back and observe some
more.  Obviously there is a cost to this in terms of space
and equipment and security ... but there is also major value,
in terms of showing them how things should be done.