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Re: PER-based textbooks (some ideas)




clement@HAL-PC.ORG writes:


I would
however try to avoid plug and chug problems, and make all
problems higher in
context

Could you provide an example that illustrates the difference for
me? I think
I understand what is meant by plug and chug, but I tend to equate
"higher in
context" with "more difficult" and since some of my high school physics
students have a hard enough time as it is I need to make sure I
am properly
interpreting your terminology.

Thanks

Justin


A problem that is higher in context has more detail, some of which is
extraneous or redundant. Most standard problems supply just give the
information needed, and seldom do they require the student to generate or
ignore information. Higher context problems also can have the information
distributed in different places. For example some information is in the
text, some in the diagram, and some in a graph. Students have to then look
for and try to understand the information rather than just plugging into
formulae. Different types of problems need to be distributed rather than
just being clustered. Often the standard texts will have all one type of
problem together in a section at the back of the chapter. This encourages
just looking for the one relevant formula and applying it to all of the
problems.

High context problem solving has been successfully used in the curriculum by
the Hellers
http://www.physics.umn.edu/groups/physed/Research/CGPS/CGPSintro.htm
Their web site explains this approach. The MOP "Minds on Physics"
curriculum also uses this approach
http://umperg.physics.umass.edu/projects/MindsOnPhysics/default
The MOP site also has some sample materials using cooperative group problem
solving of higher context problems. This might give you a flavor of the
style of problem that can be useful.

The higher context problem is in a sense more difficult, but in groups
students can generally handle them. As a result students do fewer problems,
but more difficult ones, and most of the problem solving is done in class.
I generally have them do reflections as homework. The reflections are
designed to have them think about what they did, rather than try to solve
difficult problems at home. The Hellers' web site at UMN may be
enlightening.

With regard to homework, I was just looking at the TIMMS 1999 report and a
very interesting fact popped out. The USA is much higher than most other
countries in the frequency of assigned homework. They are actually much
higher than most of the higher scoring countries, so apparently the homework
assignments are not very effective. The standard back of the chapter
homework problems have been found to actually decrease student thinking, and
in large doses may be very counterproductive. US students also claim to do
less homework/night than students in many other countries, so it may be true
that US students do less homework than other students. On the other hand,
since this is based on surveys, it is possible that US students may claim to
do less homework than they actually do, and other students may inflate
theirs. This sort of survey problem has contributed to some large
misconceptions about behavior. Europeans generally when asked "Are you
currently reading a book?" will answer yes, but Americans will generally
answer no. This is because Europeans feel that reading a book is a sign of
intelligence, and they will answer yes if they just finished, or put down a
book never to return, while Americans will answer yes only if they are in
the middle of a book. The frequency of reading is actually very similar in
the US and W. Europe.

John M. Clement
Houston, TX