2009 February 13
Lei Bao,
Your paper, "Learning and Scientific Reasoning"
Science Vol 323 30 January 2009, reports differences in
Chinese and USA student's scores on Mechanics and
Electricity and Magnetism. The students background in
measurement units is not reported. Students in the USA do
not have a background in metric units whereas students in
China have lived their whole lives with metric (SI) units.
In the USA the teaching of science and engineering
is hindered by the need to spend class time on units. In
the USA energy is given in calories, watt hours, BTU, some
other units and even joules. This makes it necessary to
spend class time on units with the result that less time
is spent on physics.
Do you have any data on how this affects the scores
you report in the paper? Do you have data from Germany or
France where SI is used in the whole of student's lives.
Do you have any data on how long it takes a student
to learn that all energy can be expressed in joules and
that all science subjects use the same background for
energy? Does this make physics easier to learn? How much
of the difference in the position of the peaks in your
paper is caused by the different life-time exposure to
units?
It is estimated (metricationmatters.com) that the
cost for the USA to continue using inch-pound units is some
$1000 billion each year. Possibly half of this cost is in
schools. This seems to say that units have a big effect
and so might contribute to the separation of the curves
you report.
Please tell me what you know of the effect that
inch-pound units have on your results.
Thanks,
Robert H. Bushnell PhD PE
