TEACHER’S TOOLKIT
Scientific explanations and
arguments: Accessible experiences
through exploratory arguments
by Andrew Falk and Lauren Brodsky
I
t is deceptively easy to think of argumentation in
science as a stand-alone activity that happens only
occasionally. The most concrete and lasting representations of arguments in science are published
journal articles, and writing them is only a fraction
of scientists’ work. But as we described in our previous article in this series (Falk and Brodsky 2013), argumentation in science is not simply the generation
of a final product, it’s an ongoing dialogue through
which scientists build new understanding of the natural world. Scientists are constantly in the process of
constructing and critiquing arguments. They draw
on what they already know and agree upon to develop new, plausible, tentative explanations for natural
phenomena that are incompletely understood. They
examine the evidence that is available, gather new
evidence, and use both to evaluate the explanations
for how well they fit with all of the evidence. And
they describe, to themselves or to their colleagues,
in talk or in writing, how the available evidence supports one explanation over others or what further evidence would be necessar y to strengthen the cases
for the various explanations.
It is similarly easy for argumentation to become
only an occasional, stand-alone activity in the science classroom. Students might only hear the words
argument and argumentation at the end of a unit
when they are writing evidence-based arguments
as a culminating activity (Cavagnetto 2010). But for
classroom science to authentically reflect the practice of scientists, the majority of students’ learning
experiences need to integrate the practice of scientific argumentation. They need opportunities to, like
scientists, work to build an increasingly deep understanding of why natural phenomena appear and occur as they do, drawing on accepted knowledge and
based on available evidence.
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What happened to this person?
Building on the foundation of our previous article
about the nature of explanation and argument, our next
several articles will describe instructional strategies
that support making argumentation an integral and ongoing part of students’ science learning. This article
focuses on activities that use a puzzling but accessible
phenomenon to engage and familiarize students with
fundamental aspects of explanation and argumentation
early in a unit.
The dilemma of teaching a complex
science practice
In our early curriculum development work, we tried
to create opportunities for students to construct arguments about natural phenomena. Argumentation is a
complex practice that is difficult to apply skillfully, and
we wanted students to argue using the science knowledge they learned in the units. We used extreme or
unexpected situations to introduce questions scientists
are currently working to answer, presenting these phe-
TEACHER’S TOOLKIT
nomena to students at the end of a unit as an opportuskills that are involved? Figure 2 represents how we’ve
nity for them to discuss and to apply the science conbeen working to reconceptualize science instruction as
tent they had just learned. We also asked them to write
knowledge building through argumentation, culminatcomplete, formal arguments using a specific scaffolded
ing in final arguments. This article will focus on how
structure. Figure 1 represents how we thought about
we’ve been using exploratory argumentation activities
the design of these units; we incorporated a variety of
to get students started with explanation and argumenactivities to support students in increasing their scitation from the beginning of a unit.
ence knowledge and asked them to apply that knowledge through argumentation at the end of the unit.
Exploratory argumentation activities
While these situations and questions sometimes led
to great class discussions, this treatment of argumenIn our work in middle school classrooms, we’ve develtation as an independent, knowledge-application activoped an instructional activity that is an effective way to
ity failed to connect students’ experience of classroom
help students experience initial engagement and sucargumentation to the knowledge-building character of
cess with explanation and argumentation early in a new
argumentation in science. Rather than portraying arguunit. In these activities, we present students with a parmentation as the process by which science knowledge
ticular situation or phenomenon in the natural world
is continuously built, it portrayed science as a
set of already known ideas and arguments as
isolated situations where these existing ideas
Argumentation as a culminating activity
Figure 1
are used. Because they fell at the end of a unit
of instruction, arguments were presented to
students with the expectation that they would
accurately apply a defined set of science ideas.
The role of argumentation in constructing
knowledge and the use of creativity to really
figure something out through argumentation
were largely lost.
The situation presented us with a teaching
dilemma. We wanted students to have the opportunity to experience argumentation as an
ongoing creative process of figuring something out. And we wanted students to have
this experience early in their learning, to see
the role argumentation plays in building science knowledge throughout the school year.
Argumentation as knowledge building
Figure 2
However, to rigorously dig into situations
through argument takes shared knowledge
about the science content and a number of
specialized skills—the ability to make plausible explanatory claims, to describe relevant
evidence and clearly explain how it connects
to the claim, to account for possible alternative claims, etc. (von Aufschnaiter et al. 2008).
The necessary science content knowledge
and skills take time and supported practice to
build. How could we make sure that students
could experience argumentation as the ongoing sense-making process by which science
progresses without expecting full knowledge
of the content or proficiency with the various
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TEACHER’S TOOLKIT
and invite them to propose possible explanations that
would account for it being the way that it is. We select
the target phenomenon carefully; in particular it’s important to ensure that it has a few key characteristics:
1. It should be worthy of explanation. The phenomenon should be puzzling or mysterious,
something that is likely to generate a sense of
curiosity for students because it is unusual or
doesn’t fit their expectations.
2. It should be accessible. The phenomenon should
be one in which there are enough features that
are familiar to students that they will be able to
propose multiple explanations, regardless of their
accuracy.
3. It should be relevant to the unit but low
stakes. The phenomenon should relate to the
Figure 3
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Images of the dead city
content of the unit but should not be something
that you need students to get the right answer to.
Having selected an appropriate phenomenon, we
present it to students, through multimedia (photos or
video) or a live demonstration. We then invite students
to propose explanations, asking them why the phenomenon happens the way it does or how it came to be the
way that it is. First we have students develop explanations individually or talking with a partner, then we invite them to share their explanations in a larger group,
to encourage the possibility of multiple explanations.
We explicitly invite students to put forward alternative
explanations to the ones already proposed. Finally, if it
makes sense to do so, we ask students to suggest ways
that we might gather evidence that could help us support one explanation over others.
TEACHER’S TOOLKIT
Three examples of exploratory
argumentation
Figure 4
Images of the mystery animal
To illustrate this kind of exploratory argumentation
activity, we’ll briefly describe three vignette examples
in different content areas. These activities are drawn
from our own experience as teachers and curriculum
developers.
Example 1: What happened
to the dead city?
It’s the first day of what will turn out to be a unit on
plate tectonics. The teacher projects several photographs of a mysterious abandoned city with buildings
in an ancient architectural style. Some of the photos
show the bodies of people and animals, except that the
bodies are not made of flesh—they appear to be made
of stone or ash. The bodies also include surprising
details, such as the folds of clothing. See Figure 3 for
some representative images.
After introducing the scenario and presenting the
images to the class, the teacher asks students, “What
do you think might have happened to this city?” After
a brief think-pair-share, students propose a variety of
explanations—a sudden fire, a volcanic eruption, an ice
storm, an alien attack with ray guns. As students propose explanations, the teacher asks them what in the
pictures led them to think that might explain the city’s
appearance. Students respond that the bodies look like
they were frozen in place, in the midst of other activities, or that they see what appears to be a mountain or
volcano in the background of one of the pictures. The
teacher asks them what additional information they
would need to gather in order to determine whether
the various explanations might be accurate. Students
suggest searching the surrounding area for volcanoes
or testing the “bodies” to figure out what they are actually made of—if they were burned, the bodies would
probably be made of ash.
Example 2: How did this animal live?
Students are in the first days of a unit on evolution, including a focus on the relationships between structure
and function of animals’ bodies and how they fit with
their environment. Their teacher shows them several
pictures of the skeleton of an unusual animal (Figure
4) and asks them to talk in pairs about how this animal
might have lived and behaved, based on what they see.
Once students have had an opportunity to share
their ideas with their partners, the teacher invites them
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TEACHER’S TOOLKIT
to share their ideas as a whole group. Students propose
a range of behaviors: The animal was a predator, using
its giant nose and long claws to stalk and kill large prey.
The animal was a large digger; it had small eyes because it spent a lot of time underground but was heavy,
with powerful front legs and claws for breaking up and
moving dirt. The animal was a forager, sniffing out insects in old, hollow trees and logs—it could stand upright or on all fours and use its claws to tear apart the
rotten wood to get at the insects inside. The teacher
notes the way that students attend to particular structures apparent in the skeleton—the large nose cavity,
the small eye sockets, the heavy bones, the large front
claws—and think about how the animal might have
used them. He asks them where they are getting their
ideas about different animal behaviors, and students
talk about a variety of other animals that have similar
kinds of features and behaviors to the ones they identified and described—lions, moles, badgers, and bears.
Example 3: Why does 500 + 500 = 980?
On the first day of a unit on the particulate nature of
matter, the teacher begins the period with a short demonstration. She pours 500 mL of rubbing alcohol into
one graduated cylinder and 500 mL of water into another, walking around to show students the levels in the
cylinders. Then she pours the alcohol into the cylinder
containing the water. She walks around once again so
students can see that the 1,000 mL graduated cylinder
contains 980 mL of liquid.
The teacher prompts students to individually write
or draw explanations for how this could happen. After
five minutes of individual work, she invites them to
share their thinking, having some students come up to
project their drawings using the document projector.
Students have a range of ideas: Some think that some
of the liquid evaporated while it was poured from one
cylinder into the other. Others think that part of the
alcohol dissolved into the water, the way that salt can
dissolve into water when it is mixed in, but only up to
a point. Another student thinks that some of the two
liquids chemically reacted and disappeared.
The teacher asks students if they have ideas about
ways they could test their explanations to see if they
are accurate. The student who proposed the idea about
evaporation suggests first putting the liquids in the cylinders on a balance to measure their mass, then mixing
them, and finally checking the mass again. If some liquid evaporated, the mass should go down. She points
out this would only tell them if that explanation was
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wrong—if the mass did change, it would fit with the
chemical reaction idea, too.
What these activities can teach students
These activities provide an early opportunity to highlight for students some of the important features of
explanation and argumentation that we described in
our previous article (Falk and Brodsky 2013).
Scientific arguments begin with questions about the natural world that call for explanations. These activities
start with a demonstration or records of an occurrence
or situation in the natural world, then they ask students
to give an account of why it occurs or how it came to be
as it is. By doing so, they present students with a target
phenomenon and ask them to construct and propose
possible explanations. When debriefing these activities
with your own students, you can highlight that what
they were doing was constructing possible explanations for natural phenomena.
Explanations include unobservable components or processes. All of these examples begin with an observable
phenomenon in the world and prompt students to propose explanations for how or why that phenomenon
came to be as it is. As students begin to consider the
phenomenon and propose explanations, they have to
go beyond the things they can immediately observe
and suggest processes and interactions that have not
been observed. Sometimes this is because events have
occurred in the past and must be inferred from what
is still present, such as the dead city and the mysterious animal. Other times it is because there are interactions between components that cannot be directly
observed, such as the mixing of the liquids. Regardless, these activities press students to make reasoned
inferences about the causes of an observable target
phenomenon. As you discuss their explanations with
them, you can point out the way that students are using the things they can observe to make inferences
about the things that happened or are happening that
they cannot observe.
Scientific arguments attempt to determine the best of
multiple possible explanations. By providing time for
students to develop explanations individually or in
smaller groups, the activities make it likely that they
will produce a variety of explanations, all of which
have some potential to account for the phenomenon.
TEACHER’S TOOLKIT
By inviting students to share their different explanations with the whole class, the activities can help them
realize and appreciate that multiple possible explanations can exist, and there is not always enough information or knowledge immediately available to decide
among them. As students propose explanations, you
can point out to them that there are often situations
in science where scientists develop multiple possible
explanations and must engage in additional investigation and argumentation to figure out which is the best.
Scientific arguments are part of an ongoing dialogue
within the scientific community. In the examples, students are prompted to think about what evidence they
are drawing on (e.g., the behavior of similar animals)
or what additional evidence they would want to gather
to help them support or test the different explanations they propose (e.g., measuring the mass of the
two liquids). By doing so, the activities create opportunities to emphasize the way that argumentation in
science is an ongoing dialogue within the community.
Scientists draw on relevant ideas and examples that
they are already familiar with and confident in and
seek new evidence that will help them to support or
refute the multiple alternative explanations they are
considering. In wrapping up these activities, you can
encourage students to think about how, as they develop understanding of new science concepts, they
build on ideas they already have and use evidence to
support new explanations.
Getting started and going further
To prepare for exploratory argumentation activities,
we recommend keeping an eye out for examples of
phenomena that connect to important science topics
that you teach and that are likely to pique students’
interest. Gather and archive photographs or video records of these phenomena or develop ways to demonstrate them firsthand. Then use the phenomena that
connect with various science topics to engage students in explanation and argumentation at the beginning of a unit and elicit their prior knowledge.
Making these exploratory argumentation activities
a low-stakes, easy-access experience for students is the
top priority when they are new to scientific argumentation. However, after several units in which students experience scientific argumentation as a central process
for building knowledge, they may be ready to do more
than simply propose initial explanations and discuss the
kinds of evidence they might need to test those explanations. If your students are ready to do more rigorous
argumentative thinking, find options for taking the next
step with this article’s online connections (www.nsta.
org/middleschool/connections.aspx).
Conclusion
Argumentation and explanation are at the intellectual
heart of scientific knowledge building. Because of
this, they are at once essential and complex science
practices that are difficult to do well, but also activities that students should authentically experience and
participate in starting early in their science learning.
We think that exploratory argumentation activities,
centered around explaining a puzzling but accessible
phenomenon, will help students experience at the outset of a unit the key elements of the creative explanation building and testing that drive argumentation. In
turn, this will help them to subsequently appreciate
the process of iterative evidence gathering and argumentation that develops and refines science knowledge. In subsequent articles, we will describe strategies for supporting students in building and using
science knowledge through argumentation throughout instruction. n
References
Cavagnetto, A.R. 2010. Argument to foster scientific
literacy: A review of argument interventions in K–12
science contexts. Review of Educational Research 80
(3): 336–71.
Falk, A., and L. Brodsky. 2013. Teacher’s Toolkit: Scientific
explanations and arguments: Understanding their
nature through historical examples. Science Scope 37
(3): 61–69.
von Aufschnaiter, C., S. Erduran, J. Osborne, and S. Simon.
2008. Arguing to learn and learning to argue: Case
studies of how students’ argumentation relates to their
scientific knowledge. Journal of Research in Science
Teaching 45 (1): 101–31.
Andrew Falk ([email protected]) is a
science curriculum development specialist and
Lauren Brodsky ([email protected]) is an assessment development specialist, both with the
Learning Design Group at the Lawrence Hall of
Science at the University of California, Berkeley,
in Berkeley, California.
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