Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

[Phys-L] Re: student difficulties with velocity as a vector?



No, it is not that they are not paying attention, it is that they do not
understand what you are saying. While there are certainly some that are not
paying attention, for others your assumptions and theirs do not line up so
that what they decode is not what you intended to convey. Then there are
others for whom there is a lack of certain underlying thinking skills. 2
dimensional vectors require the ability to do 2 variable reasoning, and
there are students who are not there yet.

If lectures and multimedia worked, then one would see a slight difference
between well crafted ones, and poor ones. But Hestenes experimentally found
that there is absolutely no difference. Incidentally at AZ state an
experiment in the intro chem. Course found that students who didn't attend
lectures tended to do better. Hake confirmed Hestenes results, and Feinman
before them also observed this. The latest issue of AJP has and article by
McDermott& Shafer which is a must read if you wish to begin to understand
the depth of the problem. Her solution, of course, is a set of tutorials.

While the term interactive engagement implies paying attention, it is much
more. It requires the students to ask what if questions or do
hypothetico-deductive reasoning. It requires students to activate prior
misconceptions so they can experience the "Piagetian" surprise. It supplies
powerful physical examples of why their reasoning is not working. For
example the Mazur method requires students to check their understanding at
various points and synchronized it with the lecturer. This works fairly
well when the students are reasonably close in level and all have high level
thinking. It does not work with lower level students at all as well, or
with widely spread students.

Paying attention is easy when you understand the lecturer's assumptions.
The meaning makes sense and you assimilate it. But when your reference
frame is totally different you can interpret what they are saying totally
differently. Essentially you need to accommodate, or change your paradigm.
When this happens, you will sometimes realize you are confused, and then
tune out the lecture, even while you automatically take notes.

We are all survivors of this system and we tended to understand the
lecturer, but the majority do not seem to do this. This is expecially true
of vectors, and kinematic understanding involving vectors. This comment is
totally confirmed by the McDermott article.

John M. Clement
Houston, TX



OK, Robert, I've been there. Your mistake is that you assume that what
you explain in class is relevant to the student answers. What you are
really measuring, IMO, is not the student understanding of Physics, bu the
fraction of students who pay attention during your lectures.

Dick Hake partially addressed this question in his TPR article on the SDI
labs and the inneffectiveness of even his most brillian lectures.