Promoting learning through assessment
Where Do I Put the Switch?
Uncovering Students’ Scientific Ideas During Engineering Design
By Page Keeley
A
fter completing a science
unit on transfer of energy,
including how chemical energy from a battery is converted to
electrical energy; electrical circuits;
and transformation of energy into
sound, light, or heat; the students in
Mrs. Finlay’s fourth-grade science
class were challenged to use what
they learned to solve a problem. The
students engaged in the engineering
design process they had been using
to develop and test a device that required a complete circuit. Mrs. Finlay supplied batteries, wires, light
bulbs, buzzers, and switches. The
students could also include their
choice of additional materials. Mrs.
Finlay used this project to assess the
NGSS fourth-grade performance
expectation 4-PS3-4: Apply scientific ideas to design, test, and refine a
device that converts energy from one
form to another (NGSS Lead States
2014) [Note: This is a hypothetical
scenario].
The student teams began by identifying a problem. The blue team
chose the problem of how to communicate on the Moon. They decided to
create a signaling device that could
be used by astronauts to communicate different signals when exploring
the Moon. They considered the constraints, recognizing there was no air
on the Moon to transmit sound, so
that eliminated the use of a buzzer.
The device had to be lightweight,
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portable, and easy to use. They brainstormed ideas to solve the problem,
choosing what they thought would
be the best solution. They decided to
make a handheld device that would
work like Morse code, except that the
signals would be different patterns
of blinking lights. It would convert
chemical energy from the battery to
electrical energy to light energy. The
astronaut would operate a switch to
make the light blink. They started
planning how they would construct
the device by making a drawing. Mrs.
Finley circulated throughout the
class, carefully listening and observing as students discussed their ideas
and planned their devices. As she
stopped to listen to the blue team, she
heard and observed the following:
Rick: “We should put the switch
here.” [He starts to draw a switch
between the wires coming from the
bulb and the positive end of the
battery.]
Jose: “No, no. The switch has to
be on the other side. The electricity
comes out of the negative end.”
Iris: “Yeah, I agree with Jose. If
you put it on the bumpy side of the
battery, the electricity won’t get to
the switch.”
Rick: “Okay, we’ll put the switch
here.” [He draws the switch
connected to a wire going to the bulb
on one end and the negative terminal
of the battery on the other end.]
Ruby: “Hmmm…I’m not sure it
matters which side we put it on.”
As Mrs. Finley listened to their
discussion about where to put the
switch, she wondered if other students had similar ideas about where
to put a switch. She thought about
the activity her students had experienced making complete circuits that
included a switch. They raised and
lowered the switch handle to observe
the difference between a closed and
open circuit. They then discussed
how the switch worked. She realized
the question about where to put the
switch never surfaced, probably because students were merely following the diagram she projected on the
Smartboard to attach their switches.
She decided this was a “formative
assessment moment” when she remembered there was a formative
assessment probe in her collection,
“Where Do I Put the Switch?”,
which uncovered students’ ideas
about whether a switch needed to
be connected to a specific end of
the battery (Keeley and Harrington
2014). She decided to use the probe
(Figure 1) at this point during the
lesson to gather more information
about her students’ thinking related
to switches and batteries.
FIGURE 1.
Where Do I Put the Switch? probe.
She asked students to pause in
their design process and turn their
attention to her. She said, “I stopped
you because I heard several students
discussing where to put the switch.
It seems there are different ideas
about which end of the battery the
switch should be connected to in order for it to work. I’d like you to take
a minute to think about this.” She
projected the probe on the Smartboard and gave the students a few
minutes of think time to jot down
some ideas.
After the students had a few minutes to share with a partner in order
to articulate and refine their thinking, Mrs. Finlay facilitated a science
talk with the whole class. She was
surprised to learn that most of the
students thought that the switch had
to be connected to a specific terminal
on the battery. The students had different ideas about which end of the
battery the switch should be connected to, and several students, who
chose Felicia, correctly described
how, when the circuit is closed, the
current flows from the negative end
to the positive end. Mrs. Finlay realized these students were recalling
a diagram she used with the class
that traced how electricity flows
from a battery. Even though these
students were correct about direction of flow, she realized they were
thinking of the flow of current as
being sequential, rather than happening at the same time. Furthermore, after having read the research
summary in the teacher notes that
described Shipstone’s study (1984),
she learned that her students’ ideas
mirrored the research. The research
found that 80% of 13-year-old students who were asked a similar
question had a sequential model of
a circuit in which electricity comes
out of the positive end of a battery
and goes through each part of a circuit in turn, returning to the battery,
so that the switch needs to be on
the positive side in order to control
lighting the lamp. Furthermore, Tiberghien’s 1983 study suggests that
using diagrams to show the flow of
current from one end of a circuit to
another reinforces the sequential
model.
Realizing that addressing some
of the science content related to current, such as understanding that
even though the current flows from
the negative end of the battery, current is the same along any single
pathway in a circuit, was beyond
fourth grade, Mrs. Finlay made a
formative decision to have her students test their sequential model
before resuming their designs. By
testing their model and making
observations, this would further
support the performance expectation that involved applying scientific ideas to test a device. She had
them test the circuit by placing the
switch on both sides and observing
what happened. The students observed that they could turn the light
or a buzzer on and off, regardless of
what end of the battery the switch
was connected to. Now they could
use this scientific idea that the placement of the switch did not matter—
current still flowed through the cir-
Summer 2015
29
cuit when closed—to plan and test
their devices.
Mrs. Finley practiced formative
assessment during the engineering
design process by carefully listening
to how students were using their scientific ideas to plan and test their devices. Sometimes these ideas surface
during engineering lessons, rather
than during students’ science lessons. When possible misconceptions
surfaced, Mrs. Finley gathered more
information to find out what her
students were thinking and planned
additional instruction to help her
students revise or refine their ideas
to move them beyond their preconceptions to the scientific ideas they
would use in their planning. She also
used this information as feedback to
improve her instruction.
Engineering design problems
often involve students in applying
ideas about electricity and magnetism. Uncovering Student Ideas in
Physical Science: 39 New Electricity
and Magnetism Formative Assessment Probes (Keeley and Harrington
2014) provides numerous STEMrelated probes that can be used to
determine the extent to which students understand scientific concepts
related to electric current, magnetism, and electromagnets that can
be used in an engineering context.
Identifying and using formative as-
www.starlab.com
sessment probes that may surface
and challenge ideas confronted during the engineering design process
will help students revise and refine
their thinking so that they can apply
scientific ideas successfully. ■
Page Keeley (pkeeley@mmsa.org)
is the author of the Uncovering
Student Ideas in Science series
(http://uncoveringstudentideas.
org) and a former NSTA President.
References
Keeley, P., and R. Harrington. 2014.
Uncovering Student Ideas in
Physical Science, Vol. 2: 39 New
Electricity and Magnetism Formative
Assessment Probes. Arlington, VA:
NSTA Press.
NGSS Lead States. 2014. Next
Generation Science Standards: For
States by States. Washington, DC:
National Academies Press.
Shipstone, D. 1984. A study of
children’s understanding of
electricity in simple DC circuits.
European Journal of Science
Education 6 (2): 185–198.
Tiberghien, A. 1983. Critical review of
research concerning the meaning of
electric circuits for students aged 8
to 20 years in Research on Physics
Education. Proceedings of the First
International Workshop, 26 June–13
July, La Londe les Mares, France,
Editions du Center National de la
Recherche Scientifique, Paris (1984),
109–123.
NSTA Connection
Visit www.nsta.org/SC1509 for
the “Where Do I Put the Switch?”
probe.
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