How Do Visitors Understand the Universe?
By Mary Dussault
This article originally appeared in the
May/June 1999 issue of the ASTC Newsletter.
What causes the phases of the moon? What are
the reasons for the seasons? Is Pluto farther than the stars?
A growing body of educational research has convincingly shown
that many people—adults and children alike—hold inaccurate
(but not essential) ideas about basic astronomical concepts. The
1988 video "A Private Universe," produced by educational
researchers at the Harvard-Smithsonian Center for Astrophysics,
showed powerfully that these misconceptions or "alternative
frameworks" can be quite resistant to change even in the
face of dogged efforts to teach the correct concept. Fortunately,
parallel developments in pedagogical practice and curriculum design
have shown that students can successfully unravel their misconceptions
and improve their understanding. It is important, first, for creators
of educational experiences to be aware of students' alternative
ideas, and second, to treat these ideas not as unfortunate errors,
but rather as stepping-stones to scientific understanding. Students
must be given concrete experiences and opportunities to grapple
with their own theories directly by manipulating models and by
discussing their ideas with others.
The past decade has seen these insights from
the world of formal education increasingly applied to the world
of museum research and practice. Exhibition planners now routinely
rely on front-end and formative visitor studies to help them listen
to the learner, probe for visitors' attitudes, beliefs, and understandings
about a topic, and modify or revise their own preconceptions about
the expected visitor experience. In the domain of astronomy especially,
museums are ideal venues for experiencing concrete and visual
models of the world, but what ideas about astronomy do audiences
in informal education environments bring with them? Several museums,
including Boston's Museum of Science and the Adler Planetarium
and Astronomy Museum in Chicago, have used educational research
results and their own front-end and formative studies to think
more carefully about designing visitor experiences that "start
where visitors are" and enhance their learning and enjoyment
of astronomy. Still, the process of learning is as difficult for
exhibit developers as it is for visitors…and it's an ongoing
conversation.
In 1997 I was part of a team at the Museum
of Science developing the exhibition Welcome to the Universe.
Since the exhibition was to be in the lobby of the planetarium,
we decided that it should offer an introductory exploration of
a few key astronomical themes that would likely be part of any
planetarium experience. In particular, astronomical size and scale,
and the notion of astronomy as a science of recognizing patterns
in the sky (including seasons and moon phases), were two exhibit
themes that we explored in qualitative interviews with visitors
using props to facilitate conversation.
Patterns in the sky: Day and night and reasons
for seasons
I was familiar with the Private Universe research on student misconceptions,
but wanted to confirm for myself, and my team, the range of visitor
ideas about the reasons for seasons. Since we were planning a
specific exhibit component addressing the seasons, we also wanted
to explore what features of a physical model, and what lines of
conversation, were most fruitful for facilitating visitor learning
about earth and sun motions. At a table set up with a lamp with
a flexible mount and a free-standing earth globe, I invited visitors
to use this "earth and sun" to first model day and night,
then later to show how they would model the seasons.
As expected from the research, visitors were
far more successful at explaining day and night than the seasons.
Children as young as eight could typically find where on the globe
it was night, and most people spun the globe in order to "make
it night" at some location. Indeed this challenge of modeling
day and night was particularly good at stimulating conversations
between adult-child pairs and ultimately we made it the invitation
activity for the final exhibit component.
The day/night challenge, however, also revealed
some common alternative ideas. Echoing the formal research, a
small but significant percentage of visitors would move the globe
around the lamp to model day and night. Even more intriguing,
a number of visitors would actively raise the lamp so that the
sun was shining down on the earth from above the Northern Hemisphere.
The table was typically set by museum staff so that the lamp and
globe were the same height off the table-our assumption had been
that visitors would automatically put themselves in the God's-eye
perspective of looking down from space at this earth/sun system,
but visitors were clearly bringing to this activity their own
ideas about "up" and "down" in space.
Due to the inevitable exigencies of time and
money, we ultimately decided not to explicitly address ideas of
up and down in the exhibit, instead fixing the sun in place and
making design choices that made the orientation of the model obvious
to most visitors. I tell this story to highlight the constant
struggle of an exhibit developer striving to pay attention to
the visitor, while at the same time recognizing the limitations
of the exhibit medium for facilitating conceptual change. When
most visitors attend to our exhibits, there will be no kind interviewer
guiding them through alternative ideas.
This struggle was particularly acute as we went
on to have visitors use the model to explore seasonal change.
Fully half of the initial group of 30 visitors used the model
in ways that expressed the popular misconception that seasonal
change is caused by changing distance between the earth and sun.
Of those that recognized the tilt of the earth had something to
do with seasons, only one or two orbited the globe around the "sun" so that the North Pole maintained its orientation.
How could we build an interactive seasons exhibit model that didn't
end up reinforcing some misconceptions? What became clear in conversations
with visitors was that most people have not had experience in
manipulating three-dimensional models of the earth and sun, and
little things make a big difference in the effectiveness of the
model. Continuing conversations with visitors through formative
stages of the exhibit's development guided us to choose specific
exhibit design and labeling strategies over others-for example,
we discovered that by including a small human figure ("Rick
on a Stick") with the model, visitors could investigate how
their ground's-eye view of the sun is related to their global
position during the day and year. These strategies encouraged
visitors to make connections between their own observations and
ideas about the seasons and this three-dimensional model.
Size and scale
By necessity, astronomy exhibitions include lots of models: physical
models, computer models, visual representations. As is true for
any model, the choice of what to represent and what not to represent
inevitably ends up misrepresenting some aspect of the phenomenon
being modeled. For example, while our Reasons for Seasons exhibit
was successful in getting visitors to explore several different
features of the earth/sun system, it also tended to reinforce
the common misconception that objects in space are relatively
close to each other. An understanding of the size and scale of
astronomical systems ends up being crucial in developing conceptual
mastery of many space science topics, from the earth's place in
the solar system, to an appreciation of space science exploration
missions, to an understanding of the structure and evolution of
the universe.
To address visitors' ideas about astronomical
size and scale, several institutions have created or are planning
true scale solar system models. Last year, Joslyn Schoemer of
the University of Colorado conducted an intriguing front-end survey
at the National Air and Space Museum for the Challenger Center's
Voyage scale model solar system project. As part of the survey,
257 visitors were asked to think of some things that are found
in the "solar system." Schoemer notes that the aim of
this question was "to give project team members ideas of
how to approach certain topics, areas that visitors commonly consider
versus those that are generally overlooked, and a little insight
into some common misunderstandings held by visitors." As
might be expected, the most common answer was "planets,"
with 82 percent of visitors giving it as one of their answers.
The second most common answer, however, was "stars"
(40.9 percent), which do not belong to the solar system; and galaxies
also were named by 17.9 percent of visitors. Schoemer speculates
that in addition to misconceptions about relative distances of
stars and planets, this result may also indicate that some visitors
do not specifically associate the term "solar system"
with the sun and its family of planets, but rather with a more
general notion of "things astronomical," which includes
stars, galaxies, and even the universe. Interestingly, very few
visitors (5 percent) mentioned the Earth as a member of the solar
system, leading Schoemer to recommend that the project team look
for "opportunities…to help visitors realize their own
residency in the solar system."
Another question on the survey asked visitors
to arrange cards with these words-Moon, Sun, Saturn, Pluto, "farthest
humans have gone," and "farthest robotic (unmanned)
spacecraft have gone"—in order of distance from Earth.
Schoemer discovered another interesting finding: "Visitors
are very used to thinking of distances in the solar system in
terms of order from the Sun. Even after listening to the request,
visitors would frequently place the Sun on one side of the supplied
Earth card and Saturn on the other." She quips, "we
spent hundreds of years getting away from a geocentric universe
to a heliocentric one, and now we can't get the earthbound perspective
back!"
Picturing the universe in The Windy City
Several of the findings of this study are echoed in some open-ended
interactive interviews conducted by staff at the Adler Planetarium
and Astronomy Museum, Chicago, Ill., as they were planning for
several new galleries in their recently-opened building. Evaluators
Shauna Keane-Timberlake and Britt Raphling engaged visitors in
some picture sorting activities in which visitors were given labeled
color laser-prints of celestial objects. In one study, visitors
were asked to arrange the pictures on a large sheet of butcher
paper to create a picture of the universe. A follow-up, slightly
more directed study asked visitors to sort the pictures into four
realms which planners wanted to use as a framework to help visitors
develop a mental map of the universe's scale and structure: Near
Earth, Solar System, Milky Way, and Rest of Universe. Keane-Timberlake
and Raphling found that "Exhibit planners knew how astronomers
pictured the universe, but did not have any information on what
a visitor's picture would look like."
Keane-Timberlake and Raphling include the following
points in their summaries of these front-end data: (1) In picturing
the universe, most people spontaneously created an "Earth
stuff" category, some created a "solar system"
or "planets" category, but almost none created either
a "Milky Way" or "universe" category. (2)
Many adults created a "solar system" category. No children
created such a grouping, although many created a "planets"
category; apparently, as hinted at in Joslyn Schoemer's study,
it is common to learn about the planets without reference to what
makes them part of a "system." (3) Visitors don't know
as much about astronomical items in the realms furthest from Earth,
nor do they have as much confidence in their knowledge of those
faraway realms. (4) People conceive of the universe in terms of
what's closer and what's farther away, and less familiar things
are assumed to be farther away. (5) Some evidence suggests the
belief that stars are sprinkled throughout the universe, including
within the solar system. These results show that the scientist's
view of the hierarchical structure of the cosmos—a concept
important to understanding the principles on which the universe
as a whole operates—is not second nature to museum visitors.
Ordering space and time
As part of preliminary planning for a proposed traveling exhibition
on cosmology, I recently returned to the Welcome to the Universe
exhibition to begin a series of exploratory studies with visitors
using an image sorting approach similar to Adler's. I wanted to
probe further into visitors' ideas of how the universe is ordered,
not only in space but also in time. Visitors were given a collection
of seven images of objects in space: Sun, Moon, Hubble Space Telescope,
Pleiades star cluster, Saturn, a spiral galaxy, the Hubble deep
field galaxies. They were asked to physically order the images
in a line, arranging them first in order of actual size of object
pictured; then in order of distance from Earth; and finally in
order of age, from the most recently formed to the most ancient.
Preliminary results confirm some of the common
misconceptions highlighted in other studies: stars and galaxies
are often placed in the solar system, or their location is guessed
at; a significant minority of survey takers believe that the space
telescope is beyond the moon rather than in low earth orbit; many
visitors struggle with the relative distance placement of the
sun and Saturn, revealing difficulties with an earth-centered
perspective on solar system distances. An encouraging aspect to
this activity was that it seemed to automatically generate conversations
and questions among visitors. As pairs of visitors grappled with
arranging the objects in order of distance, you could hear them
articulating their theories:
- "[Hubble Space Telescope] was launched
into space. I don't know how far…before Sun and Saturn."
- "Sun is closer [than Saturn]."
- "[Saturn] is in orbit and can't get
closer to us than the Sun."
- "We can't see individual stars in
other galaxies, so this [spiral galaxy] must be further [than
Pleiades]."
The third challenge, arranging the images in order of age, was especially intriguing because it calls upon visitors to make explicit their theories about evolution of objects in the universe. The comments visitors made as they did this activity were slightly different from comments made in the first two-there were fewer statements of fact, more questions, and more tentative hypothesis making. Visitors recognized this thought process to be more challenging than the first two activities:
- "This [Sun vs. Saturn] could be tricky…How
did they form?"
- "Do planets form from parts of the sun
or are they things captured?"
- "How did original gas form?"
- Well, we don't know if our galaxy is
older or younger than these."
- "Didn't they all form at the same time?"
Most of the visitor studies described here were somewhat small-sample, exploratory interviews, and each opens up new questions about visitors' astronomical understandings. Taken together, however, these studies point to several patterns of strengths and gaps in visitors' mental models of the universe. Many science centers and museums have either just opened or are planning new astronomy or space science-related exhibitions. Will our new-found appreciation of the nuances of visitors' cosmic ideas make us better at creating satisfying and successful exhibit experiences? Perhaps some future summative studies will help us learn more from our visitors, thereby continuing this cosmic conversation.
References
Raphling, B. and Keane-Timberlake, S. (1997). How "Down to
Earth" Is the Universe? Visitor Behavior, 12 (1,2):
17-20
Sadler, P. (1992). The Initial Knowledge State of High School
Astronomy Students. Unpublished Dissertation, Harvard University
Graduate School of Education.
Schneps, Sadler, et. al. (1994). Private Universe. Video produced
by the Science Media Group, Harvard-Smithsonian Center for Astrophysics.
Schoemer, J. (1999). The Voyage Front-End Survey. Unpublished
working report, Challenger Center for Space Science Education.
Mary Dussault is projects manager for the
Universe! Education Forum, sponsored by NASA and managed by the
Harvard-Smithsonian Center for Astrophysics.
©1999 Association of Science-Technology
Centers Incorporated. All rights reserved.
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