🚀 go-pugleaf

A private message got me thinking about two of the goals of learning: To
develop the ability to synthesize ideas, and to transfer ideas from
one subject to another, and use them effectively.

One change I've noticed in college students in the last thirty years (it
does date me!) is that student achievement in these areas has declined
catastrophically.

It seems that anymore *nothing has transference*. Students finish a
topic or an experiment and mentally close the book on it, thinking it
will never come up again. I have some juniors, in an optics course, who
have gone through experiments locating real and virtual images by several
methods, including the method where an auxiliary optical system
(telescope or microscope) is used to 'find' and locate the position of a
virtual image formed by a lens system. So today they were using a
Michelson interferometer. I asked them "Where are the fringes?" Blank
looks. I asked "Why should the fringes be anywhere?" Blanker looks. So I
ask "How could you find out where they are?" Nothing. I hand them a small
short working distance telescope. "Perhaps you could use this." They had,
several weeks ago, used it to find virtual images in an optical system.
They looked confused. "Aren't the fringes a virtual image?" I asked. Well,
I think you know where it went from there. I had to actually *show* them,
which is the teacher's ultimate admission of defeat.

Later I suggested they read Michelson's own book _Studies in Optics_.

Where does it go wrong? Why can't today's students make connections and
synthesize ideas? With the same course content and methods of instruction
students 15 or 20 years ago were doing these things by themselves, on
their own initiative, with no help or hand-holding from me. Now they don't
even ask intelligent questions.

A related concern: Students have been so used to labs where they followed
"cook-book" instructions, and filled in "pre-formated data sheets" that
they have no ability to *make an experiment* from scratch. They were
presented with the interferometer and a Michelson interferometer. They ask
"What are we supposed to do?" I say, "Do something physically meaningful
with what you have in front of you." I had to actually suggest that they
might measure the wavelength of the sodium light, and the wavelength
separation of the sodium doublet. They pondered that a bit, and then one
said "Wouldn't this work better if we used a laser?" I was tempted to ask
whether they wanted to computer interface it to make it still 'better',
but I restrained myself.

I shudder to think what they will say when I ask them to write a short
essay explaining the function of the compensating plate in the
interferometer.

Perhaps those of you who teach high school physics can shed some light on
this matter.

Oh, I know the *general* answer. They have previously had too many
courses in which they didn't have to demonstrate any of these
mental skills to get a 'good' grade.

        -- Donald