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[Phys-L] Critical Thinking [Was: strange things in chem book]



The way to teach critical thinking is to put the student into situations
where they have to do the thinking. It really can not be done purely by
lecture. But lectures can be useful after much exploration. Modeling is at
least partially doing it.

Look at the work of Shayer & Adey. Seriously read their book "Really
Raising Standards". They use a method which involves the learning cycle
where the students first experience a general way of looking at something,
say proportional reasoning. Then they have some applications all of which
are completely different and do not resemble the explored situation.

Even getting a PhD does not promote critical thinking very well. I know a
teacher who got his PhD in history. He then passed on some of the really
outrageous E-mail scams which purported to expose dangerous things. Notice
how critical thinking is handled by many politicians. When the fact
checkers show that they are absolutely incorrect, they attempt to discredit
the fact checkers. Of course facts do matter, but making the correct
connection between them is also important. But it is possible to lie about
facts and convince people when the lie conforms to their existing paradigm.

The other problem is that people tend to exhibit lack of critical thinking
outside of their domain of competence. So some will buy into the old saw
that theories turn into laws. In other words they didn't exhibit critical
thinking in the domain of language. One can show the difference in
terminology by just listing examples, or by looking at a variety of sources
on the web. Truly critical thinkers will not be too dogmatic and will look
at arguments by others. Unfortunately most teaching is in the form of "this
is the only right way", which promotes the opposite of critical thinking.
And of course this is what conventional lectures do.

To promote critical thinking you have to push students to think completely.
In other words when they give an answer you have to make them show that the
answer is correct by following the chain of logic between their answer and
the known facts. I am thinking of an activity that we did where the
students compared various things on Earth or on the Moon. One student came
up with the idea that a sliding block on the Moon will go 6x the distance it
would on the Earth before stopping. So why would this be true. They said
because friction is less. I would never let them get away with that. So I
asked them how do you know this. What do you know is true and can you show
the friction is less? They were right, but even right answers have to be
fully explained.

Unfortunately few teachers are trained to use methods that actually promote
critical thinking. They do know how to present procedures and drill the
students in them. That is easy to do, but it is counterproductive to
improving critical thinking.

As to textbooks, it is nice to find the errors and by exposing them hope to
have the corrected. But in reality the publishers have no incentive to do
this. In addition students hardly ever crack open the books except to look
at the end of chapter problems. Then many of the find sites on the web
where they get the worked out answers to the problems.

Also unfortunately critical thinking will not improve because of a few tips.
To do it requires a lot of rethinking of what is done in class. You have to
radically change the methods. Modeling workshops are helpful there, but
understanding the Piagetian taxonomy of thinking is also important. There
is more that has not been well researched, but there are a few people who
are interested in doing it. Actually the early work on this problem was
done by Karplus, Renner and Lawson, but seems to have been put aside except
by Shayer & Adey. Most research has been aimed a curriculum material, and
does not have adequate underpinnings for making large improvements in
critical thinking.

I can show some proven success, but nearly as much as I would like.

John M. Clement
Houston, TX



"Perhaps we could instead discuss constructive suggestions
for how to
teach
critical thinking, including how to deal with error-filled
textbooks. As
a small step in that direction, here's a suggestion: For
homework, ask
each student (a) to find something in the textbook that's seriously
incorrect,
and then (b) to explain the corresponding correct idea."
JSD included the above quote in one of his insightful posts
to the list. I
for one an interested in suggestions on how to teach
critical thinking, a
much needed skill notable for its absence in today's
political and other
commentary.I think he may have set a task too difficult for
most high school
or general physics students. In my experience most general
physics texts
are not error filled. Oh, they have errors all right, and
many have wording
that I would prefer were different, but it takes a lot of time and a
sophisticated knowledge of physics to spot true errors (as
distinct from
oversimplifications). Nevertheless the basic suggestion is
good. I would enlarge the
search domain to include any printed material. The chance of
finding an
error with a reasonable effort is greatly increased. The
requirement to
correct and explain the statement will teach some physics too.