|
Contributed by: Council of Chief State School Officers
(CCSSO)
Item Description:
The following event deals with switches and how they can be
modified for persons who do not have the use of their hands.
In the first question students are asked to design (draw), and
describe a simple circuit and switch. Then, in the second question
students are asked to design and describe a modified switch.
Answers to each may be found in either question.
Before students work with switches, they first need a basic
understanding of what a simple circuit is and how to construct
one. This is why the first criterion (1) looks at whether or
not students can at least draw a circuit with a battery and
a light bulb. To be considered complete, a continuous path must
lead from one end of the battery to the bulb or bulb holder
and back to the other end of the battery. Switches are optional
here but the circuit should look similar to Figure 1 in the
student directions. Connections to the battery must be distinct.
Students are not asked to label anything in the first question
but if a circular path is not clear in any design, credit for
a complete circuit cannot be given.
The following three criteria focus on switches. Criterion 2
looks simply for a circuit and switch that would effectively
work to power and control a light. Criterion 1 and 2 give a
student two points for a working circuit and switch. Some students
may provide a short circuiting switch which is basically a wire
that when hooked up, bypasses the light and turns it off. Again,
labeling is not a factor as long as the paths are clear and
the only intentional break is at the switch.
How students design a switch, for someone who does not have
the use of the hands, is the main focus in this event. Criterion
3 looks at the design itself. Here, students must label the
switch as such or at least label the main parts of it to show
a clear switch design. If no labeling of the switch is provided,
no credit can be given. If the switch is labeled and the design
could be controlled without the use of hands, then credit should
be given. A switch that calls for the rolling up of aluminum
foil with the feet or fastening an alligator clip by mouth,
may seem impossible, but are challenges disabled people face
everyday. The student's design is limited to the materials listed
in the student directions.
Finally, criterion 4 looks at the student's description of how
their switch works. The student must address the use of some
other body part like the elbow, foot, or mouth and how the part
operates the switch. The student may receive credit here if
there is no drawing but rather a clear description of how a
person would operate the switch.
The Item:
Question #1: Draw your circuit and switch. Explain how the switch
works.
Question #2: Now figure out how you could change the design
of the switch so that a person without the use of his or her
hands could use it. Draw a diagram of your circuit showing the
changes to the circuit and switch that would allow a person
to turn it off and on without the use of hands. In your drawing,
you must show all parts of the circuit and the switch. Each
of the parts must be clearly labeled. Explain how this switch
works.
MAIN CONCEPTS
- A complete circuit is one in which you can start at one
end of the battery and follow the circuit path around to
the light bulb or light bulb holder and back to the other
end of the battery. Normally, the only break in a complete
circuit is at the switch.
- A complete working circuit with a switch clearly shows
all of the circuit component connections and its design
shows that it would effectively power and control the light.
- Students should be able to draw and label their modified
switch idea. A clear design requires little, if any, explanation.
The modifications should allow a person, without the use
of his or her hands, to control the light.
- Students should be able to describe how their modified
switch works. How a disabled person actually controls the
light without their hands is important to designing a modified
switch. Drawings can not always clearly show alterations
in how a modified switch is intended to be used.
Scoring Rubric Summary
| Criterion 1: |
1) Provides a complete circuit. |
| Criterion 2: |
1) Provides a complete working circuit
and switch.
OR
2) Provides a complete working circuit and modified
switch.
OR
3) Provides a complete working circuit and short circuiting
switch. |
| Criterion 3: |
1) Clear drawing of modified switch. (Switch
or main parts must be labeled!) |
| Criterion 4: |
1) Clear description of how modified switch
works. |
Electrical Circuits and Switches Rubric
(The following criteria may be met in either question one or
question two.)
(Descriptions can be helpful in clarifying parts of the circuit
and switch drawings that are not clearly labeled.)
| Criterion 1: |
1) Provides a complete circuit (switch
is optional here), that clearly shows a circular path
from one end of the battery to the bulb or bulb holder
and back to the opposite end of the battery. Switch,
if included, is the only place a break in the circuit
may appear. |
| Criterion 2: |
1) Provides a complete circuit with a
simple hand operated switch, that would effectively
work to power and control the light.
OR
2) Provides a complete circuit with a modified (no hands)
switch, that would effectively work to power and
control the light.
OR
3) Provides a complete circuit with a short circuiting
switch that would effectively work to power and
control the light. |
| Criterion 3: |
1) Provides a switch design that
could be operated by a person who did not have the use
of their hands. The switch or its main parts must be
labeled to receive a point. |
| Criterion 4: |
1) Provides a clear description
of how a person operates the switch without their hands.
One example might call for a person to use their mouth
to disconnect a clip lead. |
|
|
