Re: [Phys-l] explanatory and response variables (was calibration )

[Jack Uretsky <jlu@hep.anl.gov>]

Right, I think.	Without agreement, there is no communication, hence, no 
teaching.

	Regards,
		Jack
On Thu, 9 Aug 2007, Joseph Bellina wrote:

> It seems to me that graphs are basically tools to use to solve a
> problem we are faced with, so Hugh's suggestion make sense.  It does
> mean of course that you have to agree on other conventions, as in
> this case, that the experiment results will be discussed in terms of
> cm/sec, rather than sec/cm.  Or would that be ok to use sec/cm?
>
> joe
>
> Joseph J. Bellina, Jr. Ph.D.
> Professor of Physics
> Saint Mary's College
> Notre Dame, IN 46556
>
> On Aug 8, 2007, at 11:52 PM, Hugh Haskell wrote:
>
> > At 23:35  -0400 8/8/07, Ken Fox wrote:
> > > Egad! I had no idea of how confused my students must have been as
> > > I blithely
> > > discussed that the independent variable should be on the x or
> > > horizontal
> > > axis and the dependent on the y or vertical axis.
> >
> > So what do you tell your students when they do an experiment where
> > they put photogates at fixed positions along, say, a tilted air
> > track, and measure the times that the glider passes them. Have they
> > not done an experiment where the independent variable is distance and
> > the dependent variable is time? And if so what do you tell them when
> > they plot time on the y-axis and distance on the horizontal, and find
> > that the velocity measurements come out in sec/m?
> >
> > Why worry about dependent and independent at all? If they are not in
> > a position to figure out for themselves what the optimum way to plot
> > a graph is, then just tell them put whichever variable will be the
> > numerator of slope measurements on the y-axis and the other one on
> > the x-axis. And when they complain that their chemistry teacher told
> > them to worry about dependent and independent variables, just tell
> > them that you are freeing them from that restriction. All they have
> > to do now is to think about what they are going to do and do the
> > thing that makes most sense. That means about a million arbitrary
> > rules that they no longer have to worry about.
> >
> > Then you can take up a collection among your faculty colleagues to
> > provide help for the chemistry teacher who just had a nervous
> > breakdown, because now his most righteous rules
> > (dependent/independent variables and significant figures--see earlier
> > posts) have both been violated.
> >
> > Hugh
> > --
> >
> > ************************************************************
> > Hugh Haskell
> > <mailto:haskell@ncssm.edu>
> > <mailto:hhaskell@mindspring.com>
> >
> > (919) 467-7610
> >
> > Hard work often pays off after time. But Laziness always pays off now.
> >
> > 			February tagline on 2007 Demotivator's Calendar
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>
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