PALS

Electrical Circuits and Switches

Grades 5-8 Performance Task

Contributed by: Council of Chief State School Officers (CCSSO)

Students draw circuits and switches, explain how they work, then change their design for someone without hands to turn the switch on and off.

Administration Procedures

Description:

Students draw circuits and switches, explain how they work, then change their design for someone without hands to turn the switch on and off.

The task assesses students' abilities to follow simple instructions to build a circuit, modify the design, and describe and diagram the changes made.

This task is designed to take students approximately 20-30 minutes to complete.

Overall Task Content Area:

Physical Science

Specific Knowledge Areas:

Electrical Circuits

Performance Expectations:

using equipment
apply scientific principles to develop explanations and solve new problems.

National Science Education Standards:

8 B PS 3: Transfer of Energy: Grades 5-8

3.4 Electrical Circuits.

8 A SI 1: Abilities Necessary to do Scientific Inquiry: Grades 5-8

1.2 Design and conduct a scientific investigation.

8 E ST 1: Abilities of Technological Design: Grades 5-8

1.2 Design a solution or product.

1.4 Evaluate technological designs or products.

(Use the "hot" link on the PALS home page to check the full text of related National Science Education Standards, if desired.)

General Teacher Instructions:

Students will be working in groups of 4 - 6 for the experiment/activity part of this exercise. The following suggestions are offered to facilitate administration of the exercise.

Students need to be ready to work as soon as the period begins.
Group assignments should be made in advance.
The materials should be set out at each lab station, if possible.
A central supply area, if needed, should be easily accessible.
The supply area should have any supplies from the kit that were prepared by the teacher as well as all of the school-supplied materials necessary for the experiment.
All the supplies should be clearly labeled.

Materials for "Electrical Circuits":

1 D-cell battery and battery holder
4 clip leads (wire with alligator clip)
1 bulb and socket
3 10-penny nails
2 straws
6 3" pieces of copper wire
6 3" pieces of aluminum wire
12" x 12" piece of aluminum foil
6 toothpicks per group
25 cm of string (kite string, fishing line, thread, thin twine) per group
3 index cards per group
1 meter of masking tape
3 rubber bands per group
1 pen or pencil per student

Advanced Preparation:

Cut 3" pieces of copper and aluminum wires for each group.
Cut a 12" x 12" piece of aluminum foil per group.
Cut 25 cm of string and 1 meter of masking tape for each group.
Place materials at student work stations.
Before you administer the exercise, test each bulb to make sure that it lights.

Safety:

Be careful.
Teachers and students should always exercise appropriate safety precautions and utilize appropriate laboratory safety procedures and equipment when working on science performance tasks.

Task with Student Directions

Welcome to this experimental science test. We hope that you will find it interesting and worthwhile. Carefully read through these directions and the directions on the next page before you begin to work.

You may be part of a group for the first part of this exercise. Each group should carry out the experiment and collect the data together, but each student must record the data in his or her own booklet. Be sure to record the data exactly as you observe them. After the data have been collected, each student should answer the questions independently.

After you have finished your experiment and have recorded all of the data, you will be asked to answer some questions about the experiment and the data you recorded. Your answers must be written in this test booklet in the space provided. Make sure that you understand each question before you begin to write. At any time while you are writing your answers, you may look back at the directions for the experiment and the data you collected. Be sure that your answers are written as clearly and neatly as possible.

Before you turn the page, read the list of materials given below and check to make sure that your group has everything listed.

Materials in the Kit

1 D-cell battery and battery holder
4 clip leads (wire with alligator clips at each end)
1 bulb and socket
aluminum foil, 12 in x 12 in
6 pieces of aluminum wire
6 pieces of copper wire
2 straws
3 10-penny nails

Materials Supplied by the School

masking tape
6 toothpicks
2 index cards
3 rubber bands
25 cm string
pen or pencil

Electric Switch

Your lab team has been hired to help remodel a house so people who do not have the use of their hands will be able to turn the lights on and off.

For the device to work you will need to:

make a circuit that conducts electricity
design a switch to turn the circuit on and off
adapt your design for people who do not have the use of their hands

Step 1. Make sure you can light a bulb.

Use the materials you have been given to create the circuit shown in the diagram.

Figure 1

Does the light bulb light? If it does not, check to be sure that you have constructed the circuit properly and ask your teacher to make sure that your bulb and battery are working.

Step 2. Build a switch.

A switch is a device that can be used to connect and break the circuit so that the bulb will turn off and on. Once the bulb in your circuit lights, use the materials you have been given to create a switch. Work with your switch until you can use it to turn the light bulb on and off. Add the switch to the circuit. Each member of the group should draw a diagram of the circuit in his or her own booklet. In your drawing, you must show all parts of the circuit and the switch. Each of the parts must be clearly labeled. When you have finished your drawing, return to your desk to finish Question 1 and work on Question 2.

Questions

Please answer the following questions by yourself.

1. Draw your circuit and switch. Explain how the switch works.

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.

Rubric

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.

Technical Quality Information

These data were prepared by American College Testing (ACT) based on a field test of this Performance Event.

Unit Name:	Electrical Circuits
Unit Content:	Physical Science
Unit Theme:	Acquiring Information and Constructing Meaning

Unit Statistics:

Event Score	0	1	2	3	4
N	5.00	22.00	32.00	41.00	20.00

N	Mean	Standard Deviation	Standard Error
120.00	2.41	1.10	0.10

Examples of Student Work

There are two examples for each score point ranging from 4 to 0. Explanations of the scores were written by staff from American College Testing (ACT) who conducted training and scoring of field tested events.