What are the labs for?

[LUDWIK KOWALSKI <KOWALSKIL@alpha.montclair.edu>]

On December 12, 1997, referring to this,

> > The rule which prevails in the lab should be that "data are bad only when
> > students do something incorrectly, otherwise they should be good". That
> > does not happen with "black boxes". During our experimentation we had to
> > reject data from numerous trials knowing very well that nothing was done
> > wrongly by us. Even in the case of coffee filters we often observed 
> > strange curves and rejected them on the basis that "something is not 
> > right" basis. 
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   Jack Uretsky (JLU@HEP.ANL.GOV) wrote:

> I hope that I'm misreading this. The burden, as I understand it, is on
> the experimenter to demonstrate that the data are "good". The ultimate 
> test is that that the data are reproduced independently in a different lab.
> Deviations from expectations should certainly be investigated - consider 
> the guy who kept moving his photographic film away from the drawer 
> containing the radium ore (before the discovery or radioactivity). In other 
> words, the rejected data were just as "good" as the accepted data. The 
> rejection merely biased that experiment in favor of your expectations.

You are correct, Jack, by saying how it should be. But can this be done in
a traditional setting when the amount of time is limited? Comparing our
rejections of irreproducible data with the attitude of Buequerel toward a
strange looking film is not worth the bandwidth. But the role of the lab 
in the introductional physics course is certainly worth discussing. 

For example, should laboratory work be time-limited or not? Should it be 
cookbook-like or not? Could it be offererd as a separate unit after the 
no-lab semester is over? What are we trying to accomplish? Who should be 
conducting the labs? Wouldn't good demonstrations (on which reports must 
be written, and in which student interactions are strongly promoted) be 
more useful than traditional labs?

Please share your ideas and observations about labs in the introductory 
physics courses. I think there is a lot of room for improvements in this
area. Much more than we are willing to admit.
                                                   Ludwik Kowalski