Download Light Tasks

Assignments for Each Topic Group
1. Answer the questions as a teacher AND predict how many of your students would
answer them.
2. Fill in THE FIRST TWO LINES of the instructional representation for your topic:
 Students’ experiences, patterns, and theories that lead them to the answers that
you predict
 New qualitative experiences, patterns, and explanations that go with the correct
answers
3. Compare your instructional representation with the other group working on your topic
4. Suggest activities that would be useful for developing inquiry cycles or learning cycles
with scientific qualitative understanding as a goal:
 New experiences that don’t fit the patterns they are familiar with
o Refraction: Spear fishing demonstration, coin in cup
o Force and motion: Falling objects, weight in a vacuum, cart with constant
force
o Buoyancy: Alka-Seltzer demonstration
o Color, reflection, or intensity: ????
 New patterns that include both their old experiences and their new ones
o Refraction: Denser media make objects appear shallower than they really
are
o Force and motion: Force causes acceleration rather than motion
o Buoyancy: Floating and sinking depend on density, not mass
o Color, reflection, or intensity: ????
 New explanations that account for a wider range of phenomena1
o Refraction: We see by detecting light that bends as it goes from one
medium to another
o Force and motion: There is no “force of momentum,” but there are many
forces on objects around us close to earth
o Buoyancy: The buoyant force on an object is caused by the difference in
pressure from the fluid on the top and the bottom
o Color, reflection, or intensity: ????
1
Note that one characteristic of new scientific explanations is that they can unite domains that were
previously separate. For example, Newton’s laws united the motions of objects in the heavens and
objects on earth. Learning about light and vision is a challenge for many students because they have to
develop a unified explanation for domains that they had thought of as separate:

Light and illumination

Seeing objects

Seeing images

Seeing colors
4. Try to develop a rubric for evaluating students’ explanations that you could use for a
learning cycle like the one we used for refraction:
Part 1: The Drawing
1. Start with a drawing of the situation that includes all the relevant parts: the light source, the object,
the eye of the observer, and the different media through which the light travels
2. Draw the path of the light from the light source to the object. (This light is probably refracted along
the way, but that isn’t particularly important for your explanation.)
3. Remember that the object reflects light rays in all directions. Your job is to show the path of the
light that actually reaches the observer’s eye. Draw an arrow (bending toward the denser medium
at boundaries between media) showing that path.
Part 2: The Written Explanation
4. Write the first part of the explanation: A sentence or two explaining how the light reflecting off the
object bends on its way toward the eye of the observer.
5. Write the second part of the explanation: A sentence or two explaining how the image the observer
“sees” depends on the direction of the light entering his or her eye, not on the actual location of the
object.
EPE Type
Experiences
(Observations,
Data)
Patterns
(Generalizations,
Laws)
Student Personal
Scientific
Qualitative
Scientific
Quantitative
06/29/17, Page 2
Explanations
(Theoretical
Models)