WHAT ARE STUDENT IDEAS ABOUT LIGHT, COLOR,
AND THE ELECTROMAGNETIC SPECTRUM?
(as they relate to NASA’s MultiWavelength Universe)
Some of the assessment questions from your pre-course survey were drawn from the "MisconceptionOriented Standards-based Assessment Resources for Teachers" (MOSART) project at the HarvardSmithsonian Center for Astrophysics. You can log on to the MOSART website to take a tutorial and
download a whole set of research-based multiple-choice assessments for probing conceptual understanding
about a variety of standards-based science topics. http://www.cfa.harvard.edu/smgphp/mosart/index.html
Each downloadable MOSART instrument comprises a set of multiple-choice items that are linked to the K12 physical science, astronomy, and earth science content, and K-8 life science content in the NRC's
"National Science Education Standards," as well as to the research literature documenting common science
misconceptions. You may find individual items useful to you in developing pre- and post- evaluation tools to
measure whether your students are making learning gains after instruction.
The MOSART project has found that many teachers tend to overestimate the post-instructional performance
of their own students on these test items, perhaps due to an incomplete appreciation of how compelling
particular misconceptions may be to students and how strongly they hold on to them even after instruction.
The chart below presents the responses of course participants to the nine MOSART questions that were in
the Pre-Course Survey:
• To the right of each multiple-choice question, the first data column shows the percent of online
course participants who themselves chose the correct response for each item.
• The second data column shows how many of you predicted that any particular choice was the most
likely “Distractor” – a wrong choice that would tempt students. Note that sometimes, some of you
may have been tempted by a distractor yourselves and so suggested the correct response as a
possible distractor!
• The last column shows the percentage of high-school students (in most cases, 11th or 12th graders) in
MOSART’s national study that selected each possible answer choice. Note that sometimes a
distractor is nearly (or sometimes even much more) popular than the correct response. Items that
show this characteristic reflect concepts that are particularly difficult for students to fully
understand.
Each question is followed by a brief commentary on the responses, and we’ll ask for some of your reactions
in the Section 3 Student Ideas Discussion Forum. If you have a question about any of the assessment items
that you don’t want to post publicly in the discussion forum, you can send a message to course instructor
Mary Dussault by clicking on her profile (under “participants”) and then on “send a message”.
MOSART Question From Pre-Course Survey
NASA puts telescopes in space:
a. to get closer to the stars and galaxies.
b. because it is colder in space.
c. to get above the atmosphere.
d. because there is no gravity in space.
e. None of the above.
NASA’s MultiWavelength Universe Online Course
June 25 – July 13, 2012
% correctly
responding (MW
course
participants)
77.3%
Predictions of
which choice is
best distractor
77.3%
4.5%
4.5%
13.6%
-
Actual student
response data
(national sample)
47%
5%
15%
8%
25%
M. Dussault/CfA
The best Answer is c (15%). While student responses to this question show that they do not understand how the
Earth’s atmosphere distorts and blocks light from space, it also suggests they may far underestimate the distances to
stars and galaxies, as nearly half of students chose a.
% correctly
Predictions of
Actual student
responding (MW
which
choice
is
response data
MOSART Question From Pre-Course Survey course
(national sample)
best distractor
participants)
A photon of which kind of radiation carries the most
energy?
a. Radio
b. Infrared
c. Visible
d. Ultraviolet
e. All photons have the same energy.
68.2%
22.7%
9.1%
13.6%
9.1%
45.5%
9%
15%
7%
56%
13%
About 55% of students chose the best response, d, with other responses evenly spread among a to e, indicating
guessing. Responses to this question, the question about red, yellow, green, and blue photon energies, and other
MOSART items indicate that many students are not fully aware of how different portions of the em spectrum are
associated with phenomena of different energies.
In order for scientists to detect distant objects in
space, electromagnetic radiation must:
a. reach a detector.
b. be converted into matter.
c. be converted into light.
d. be converted into radio waves.
e. be converted into energy.
81.8%
22.7%
4.5%
45.5%
27.3%
21%
9%
21%
38%
10%
This question probes student understanding of the idea that objects in space emit light; that light (of any energy or
wavelength) IS electromagnetic radiation that travels through space; and that that light must reach a detector to be
“seen” or detected. The Sources and Shields activity from the Invisible Universe GEMS guide helps student explore
this concept.
NASA’s MultiWavelength Universe Online Course
June 25 – July 13, 2012
M. Dussault/CfA
MOSART Question From Pre-Course Survey
Zahra is sitting in her backyard, looking at a tree. With which of
the following statements about how she is able to see a tree do
you agree? (See diagrams)
a. Light from her eye reaches the tree and she sees the tree.
b. Light from the Sun reaches the tree and then her eye and she
sees the tree.
c. Light from the Sun reaches her eye and she sees the tree.
d. Light from her eye reaches the Sun and then the tree and she
sees the tree.
e. Light from the tree reaches the Sun and then her eye and she
sees the tree.
% correctly
responding
(MW course
participants)
Predictions of
which choice is
best distractor
Actual student
response data
86.4%
50%
13.6%
14%
54%
22.7%
9.1%
12%
12%
4.5%
6%
(national
sample)
Slightly more than half of the students correctly understood that we see objects only when light is scattered from the
object (or emitted by it) and that light then enters the eye. The other students chose fairly equally among the
other options, each of which involves the eye behaving in some sort of active manner, rather than its real behavior as
a passive receiver; this notion of vision is a dominant misconception into high school.
An astronomer wants to build a telescope that only detects Xrays. Would other astronomers think this was a good idea?
a. No, because no astronomical object gives off X-rays.
b. No, because X-rays from outer space are too
dangerous to work with.
c. No, because X-rays from astronomical objects provide
no useful information.
d. Yes, but new technology would have to be invented; no
such device has ever been built.
e. Yes, this has already been done.
77.3%
31.8%
22.7%
11%
16%
13.6%
16%
27.3%
25%
4.5%
33%
Student responses to this item suggest that the story of NASA’s multi-wavelength universe can definitely help students
to better understand the electromagnetic spectrum through astronomical examples of sources and detectors!
A photon of which color light carries the most
energy?
a. Red light
b. Yellow light
c. Green light
d. Blue light
e. All photons have the same energy.
68.2%
59.1%
4.5%
4.5%
31.8%
34%
11%
8%
33%
15%
D is the best answer, chosen by only 1/3 of students in grades 8-12. More students actually chose a. than d., indicating
that the important relationship between energy and wavelength is not well understood by students.
NASA’s MultiWavelength Universe Online Course
June 25 – July 13, 2012
M. Dussault/CfA
MOSART Question From Pre-Course Survey
How do radio waves and x- rays differ?
a. They travel at different speeds in a vacuum.
b. Only radio waves can be reflected.
c. They have different wavelengths.
d. Only two of the above are true.
e. a, b and c are all true.
% correctly
responding (MW
course
participants)
54.5%
Predictions of
which choice is
best distractor
45.5%
9.1%
9.1%
18.2%
18.2%
Actual student
response data
(national sample)
3%
4%
41%
32%
20%
While the correct response was the most frequently chosen, this item reveals that the idea that different wavelengths of
light may travel at different speeds still may “make sense” to many students.
Sunlight transfers energy to the Earth's surface
mostly in the form of:
a. visible light.
b. microwaves.
c. ultraviolet light.
d. radio waves.
e. All of the above.
50.0%
45.5%
4.5%
50.0%
16%
7%
37%
7%
32%
This question is conceptually difficult, because it calls on understanding of several different phenomena related to the
em spectrum, including: that while the sun emits energy across the entire em spectrum, it emits most of its energy in
the middle of the visible wavelength region (and is thus yellow) because of its 6000 degree C surface temperature (if it
were hotter, it would be bluer, but would have to be much hotter to emit more UV than visible light). The question also
asks about energy that reaches the Earth’s surface, and while we are all taught to protect ourselves from the sun's
ultraviolet light, most UV light (but not all) is in fact blocked by the Earth's atmosphere (as are many other wavelengths
of light beyond the visible). Students may also be confused if they know that UV light is more energetic than visible
light – while this is true for individual photons, the total amount of solar energy that reaches the earth’s surface is
carried mostly by the vastly greater quantity of photons of visible light that the sun is emitting.
If you looked at a continuous spectrum in a darkened room
through a red filter, the spectrum would appear:
a. the same except the red portion would be black.
27.3%
b. black except the red portion would remain red.
50.0%
8%
c. as shades of red except the red portion would be black.
9.1%
d. as shades of red except the red portion would be a
45.5%
52%
brighter red.
e. the same as if there was no filter present.
18.2%
Few students chose the correct answer, B, while 52% chose D, highlighting a very common misconception
concerning colored filters. I.e., that they add their color to the light passing through them or otherwise add their color
to a scene
MOSART is funded by the National Science Foundation’s Math Science Partnership Program, and the development of
the K-12 Astronomy and Space Science Concept Inventory items was funded by NASA’s Science Mission Directorate
through the Universe Education Forum.
NASA’s MultiWavelength Universe Online Course
June 25 – July 13, 2012
M. Dussault/CfA