Section 1 - About Workshop Five:
"Where Should We Start?"
What is the theme of this workshop? The theme of Workshop Six
is "choosing a goal for conceptual learning."
Whom do we see in the video? Robert, a new teacher, discovers
that sixth graders create models to predict the motions of objects. With
this information as a foundation, how should Robert proceed with his lesson
plan for next term?
What happens in the video? The concepts of friction and
energy dissipation are inventions of science. If the teacher tells
the students to "ignore friction," will the students know what
that means? If Robert presents a new problem in a different context, will
his students accept and correctly apply the scientists' counter-intuitive
definition of friction?
What problem does this workshop address? We all live in a world
dominated by friction. When we ice-skate or slip on a banana peel, friction
is reduced for a time, but it is never entirely removed. Students, however,
are asked to "imagine a world without friction" when studying
force and motion. Faced with the conflict between the world of everyday
experience and the frictionless world they are asked to imagine, how are
children to make sense of the lesson?
What teaching strategy does this workshop offer? This workshop
examines how students and teachers can work within a scientific view. The
particular challenge is developing lessons that serve as bridges from the
learner's experience to the scientist's view. In order to achieve this link,
the teacher must first set content goals and elicit student ideas to make
clear the gap between the learner's experience and the science idea. The
lesson then becomes a platform across which the student can move from understanding
ideas in an "everyday" context to understanding them in a "science"
context. This strategy is called bridging and often employs analogies.
Section 2 "Where Should We Start?"
A. The Goals for Workshop Six
"Where Should We Start?" is for teachers interested
in new ways of creating lesson plans, selecting appropriate educational
strategies, and addressing student assessment.
The goal of this workshop is to reach such teachers.
How can teachers create lessons that start from the students'
The newest educational strategies are necessarily first implemented under
special conditions. Therefore, in portraying a specific instructional approach,
these strategies may not seem to apply to everyday classroom experiences.
Can lessons learned in a "lab-school" setting be relevant
in more typical classrooms? (A lab-school setting refers to classrooms
established in designated schools for the purpose of testing and evaluating
new teaching approaches.)
Section 3 - Exercises
A. Exercise: Responding to Workshop Six
One of the important scientific ideas explored in this workshop is friction.
The following exercise is for teachers, but can also be used in the classroom
as a student exercise to explore the concept of friction.
Write a series of fictional diary entries in which you are suddenly
transported to a world without friction.
How is this world different from ours?
What are some of the first things you notice in this new world?
In what way is life improved in a world without friction?
In what way is it made worse?
What sorts of inventions and/or machines are made possible or impossible
in a world without friction?
B. Exercise: Preparing for Workshop Seven
You will get the greatest benefit from the next workshop if you complete
the following exercise. Ask students, colleagues, friends, and yourself
the following question.
Leaves fall off trees and eventually turn to dirt. Is the Earth
getting bigger and bigger as the dirt from the leaves accumulates? Why
or why not?
Section 4 - Educational Strategy
A. Anchoring Examples and Bridging Analogies
Another example of "bridging analogies" as a teaching strategy
can be found in the materials for Workshop Five: "Can We Believe Our
Own Eyes?" This strategy may be effective when the student finds a
concept especially implausible but thinks that a related concept is obviously
true. The concept that the student already accepts becomes the anchoring
example. The teaching task becomes to use lab activities, discussion,
or other approaches to help the student build a bridge between the anchoring
example and the target concept. The pieces of this bridge are called bridging
analogies. Here is an example with bodies in motion. This example will
also help develop students' skills in graphing and extrapolating from data.
In this approach we take a cue from Galileo. The target concept that
we want the students to understand is contained in Newton's first law of
motion. (See Section 3, Part B: "Historical Ideas" for discussions
of Galileo and Newton.) The anchoring example is a phenomenon that, according
to the research, most children believe. This phenomenon is embodied in the
fact that a ball rolled on a surface of high friction will quickly come
to a stop. The bridge to the target concept is built by rolling the
same ball with the same initial force on surfaces of less and less friction.
As the students graph the results, they may come to see that the ball could
roll on "forever" if all friction could be removed. Even though
we can never completely remove friction from the exercise, we can help make
Newton's law more plausible for many of the students.
Materials for Experiment
Marbles or small balls of uniform size and weight.
Surfaces of various degrees of friction. These surfaces could include
lengths of deep pile carpet, medium pile carpet, flat indoor-outdoor carpet,
rough wood, polished wood, tile, etc. If performed outdoors, surfaces could
also include deep sand, loose dirt, tall grass, freshly-mowed grass, and
concrete. In all cases, care must be taken to determine that the surface
A "starter." The starter device must be able to start the
ball rolling with about or nearly the same force each time. The spring-loaded
plunger from an old pinball machine would be more than adequate. (This
device propels the steel ball into the body of the pinball machine at the
start of each game.) The teacher and students could also try to invent
a good starter from rubber bands, based on the principle of a sling-shot.
In this case the model should not be a very strong sling-shot. In the absence
of a mechanical device, a student or the teacher could start the ball each
time with a flick of a finger, attempting to duplicate the force on the
marble with each start. This last method, however, raises the conscious
or unconscious suspicion of bias or "cheating" on the part of
Predict: Before rolling the marbles or balls over the various
surfaces, the teacher asks the students to predict what will happen. Do
they expect the balls to roll farther over some surfaces, less over others?
Which surfaces will permit longer "trips" by the balls and why?
Measure and Record: During the exercise the "starter"
is used to propel the marble or ball over each of the surfaces. Students
should carefully measure and record the length traveled by the ball in each
trial. For further accuracy, several tries can be made over each surface
and the results averaged.
Graph Data: After all of the measurements are recorded, students
can work alone, in small groups, or as a class to graph these data. A graph
can be created with the lengths traveled on one axis plotted against the
various surfaces on the other axis. Arrange the graph so that the data on
it progress monotonically from the shortest trip to the longest one. Ask
the students how well the data fit their predictions. Ask them to explain
the pattern they see in their graphs.
Discuss: By drawing a curve through the data points, students
can infer that the ball rolls farther across surfaces that offer less "resistance."
This resistance is called "friction." By extending the curve,
you can help the students extrapolate to the behavior of a ball rolling
across an ideal frictionless surface. As with any strategy, this activity
will leave some children unconvinced. Some students, however, may come to
accept that in a frictionless situation, the ball would roll "forever"
without stopping-if the surface were long enough.
Section 5 - Resources for Workshop Six
Companies, publications, and organizations named in this guide represent
a cross-section of such entities. We do not endorse any companies, publications,
or organizations, nor should any endorsement be inferred from its presence
in this guide. Descriptions of such entities are for reference purposes
only. We have provided this information to help you to locate materials
A. Related Resources
Interactive Physics II-a computer program. For information contact:
15 Brush Street
San Francisco, CA
Ardley, Neil. 1992. The Science Book of Energy. San Diego: Harcourt
Brace Jovanovich, Publishers. To order:
Harcourt Brace and Company
525 B Street, Suite 1900,
San Diego, CA 92101
TOPS Learning Systems
10970 South Mulino Road
Canby, OR 97013
B. Further Reading
Goldstein, M. and I. Goldstein. 1993. The Refrigerator and the Universe/Understanding
the Laws of Energy. Cambridge, MA: Harvard Press.
Gonick, L. and A. Huffman. 1990. The Cartoon Guide to Physics. New
York: Harper Perennial.
Krauss, L. M. 1993. Fear of Physics/A Guide for the Perplexed.
New York: Basic Books.
Hollander, J., ed. The Energy-Environment Connection. Washington
DC: Island Press.
Ronan, C. A., ed. 1993. Science Explained/The World of Science in
Everyday Life. New York: Henry Holt and Company.
C. Bibliography on Energy
Bliss, J. and J. Ogborn. 1985. Children's choices of uses of energy.
European Journal of Science Education 7: 195-203.
Brook, A. 1987. Designing experiences to take account of the development
of children's ideas: An example from the teaching and learning of energy.
In Proceedings of the Second International Seminar on Misconceptions
and Educational Strategies in Science and Mathematics (Vol. III, pp.
84-97), J.D. Novak, ed. Ithaca, NY: Department of Education, Cornell University.
Brook, A. and R. Driver. 1986. The construction of meaning and conceptual
change in classroom settings: Case studies of energy. Leeds: UK University
Carr, M., V. Kirkwood., B. Newman and R. Birdwhistel. 1987. Energy in
three New Zealand secondary school junior science classrooms. Research
in Science Education 17: 117-128.
Duit, R. 1981. Understanding energy as a conserved quantity. European
Journal of Science Education 3(3): 291-301.
Erickson, G. and A. Tiberghien. 1985. Heat and temperature. In Children's
Ideas in Science, R. Driver, E. Guesne and A. Tiberghien. Philadelphia:
Open University Press.
Gunstone, R. and M. Watts. 1985. Force and motion. In Children's Ideas
in Science, R. Driver, E. Guesne and A. Tiberghien. Philadelphia: Open
Solomon, J. 1982. How children learn about energy or does the first law
come first? School Science Review 63: 415-442.
Solomon, J. 1983. Learning about energy: How pupils think in two domains.
European Journal of Science Education 5: 49-59.
Solomon, J. 1992. Getting to know about energy-in school and society.
London: The Falmer Press.
Warren, J. 1986. At what stage should energy be taught? Physics Education
Watts, M. 1983a. A study of school children's alternative frameworks
of the concept of force. European Journal of Science Education 5:
Watts, M. 1983b. Some alternative views on energy. Physics Education