Download NARST Conference Rio Grande, Puerto Rico April 9, 2013

STeLLA Focus on Student Learning: Elementary
Students’ Ideas about Earth’s Changing Surface
Connie J. Hvidsten & Elaine V. Howes
NARST Conference
Rio Grande, Puerto Rico
April 9, 2013
Context of the Study
• Creating a STeLLA
videocase
• How videocases are
used in STeLLA
Professional
Development
STeLLA Videocase
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•
•
•
Earth’s changing surface
Two fourth-grade classrooms
Six lesson unit
Classroom video
Teacher interviews
Two interviews with three
students from each class
• Student work
Theoretical Framework
• Constructivism/Conceptual Change
If students construct new knowledge using knowledge
they already have, what’s the stuff they already have
that they can use?
Hammer & van Zee, 2006, p. 15
• Developing Learning Progressions
If mastery of a core idea in a science discipline is the
ultimate educational destination, then well-designed
learning progressions provide a map of the routes that
can be taken to reach that destination.
NGSS Framework, 2012, p. 11
Research Questions
• What causal mechanisms do these students invoke
to explain Earth's surface changes over time?
• In what ways did these students’ ideas change in
these STeLLA classrooms?
Methods
• Interview approach
– STeLLA questioning strategies
– Multiple representations
• Interview analysis (Delamont, 2002, Erickson, 2012)
– Look for recurrent patterns and contrary instances to
patterns
– Compare and revise patterns and contrary instances
– Carry out multiple iterations
– Construct generalizations based in these data and
analysis
Learning Goals
1. Earth’s surface has recognizable features/landforms, and these
landforms are constantly changing.
2. Some of the processes that change Earth’s surface result in the
tearing down of surface landforms. Erosion is one process that
tears down landforms by transporting weathered earth materials
from one place to another over time by wind and water.
3. Some of the processes that change Earth’s surface result in the
building up of surface landforms. These processes include
deposition of sediments, volcanic activity, and crustal uplift.
4. At any given point in time, Earth’s surface is going up in some
places and wearing down in others. It can happen quickly in some
places and slowly in others.
Findings: Prior to Instruction
• Generally, Earth’s surface landforms
are permanent.
• Any changes in Earth’s surface due
to earthquakes or volcanoes.
• It is hot inside of the Earth (water,
fire, volcanoes).
• Rocks break down because they get “old” and “weak.”
• No mention of the influence of water on changes to
Earth’s surface.
• No mention of plate movement.
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Findings: Intermediate Constructions
• Rocks can get smaller through
weathering
– Local vs. global
• Plate movement adopted as the
causal mechanism for all changes in
landforms
– Small scale landforms
– Formation of individual mountains
associated with plate movement
– Plate movement explains decrease in
elevation of mountain ranges
Marta: Plate movement explains
everything
Marta: [When plates come together] they build
mountains. And when they come apart they don’t build
mountains. They shrink the mountains.
Interviewer: So you’re also saying that when the
mountains could be built up like this [pushing the plates
together to represent collision and mountain building],
and then … what happens when the plates start pulling
away?
Marta: It makes the mountain flat.
Greg: Holding two ideas at once
Interviewer: Are there any other things that might cause
these mountains to become flatter besides the plates
moving apart?
Greg: Oh, yeah, the snow, like how I said ice can, if it gets
inside a rock can get make it like explode, and like if it
gets snowing and ice keeps getting in rocks, rocks might
keep exploding and fall down and the mountain might get
smaller and smaller.
Nathan: Adopting new ideas
Interviewer: Can you show me using the arrows and
these foam pads how plates move?
Nathan: The plates are connected kind of, and if they
move this way [moving away from each other, creating a
gap between them] it will create a canyon … that will
open up the Earth and it might spread out magma over
the surface and that will create another crust…but if it
connects to each other, goes toward each other [moving
the arrows to point toward each other] it will collide and
hit each other and go up. And that’s kind of like a
mountain and that will kind of form a mountain.
Findings: Adopting Science Ideas
• Each type of plate movement results in different
types of surface features.
• The movement of tectonic plates results in the
formation of volcanic and non-volcanic mountains
and causes earthquakes.
• The processes of weathering and erosion can break
rocks apart and move them to different places in a
localized way.
Implications
All research on student conceptions of science is motivated by
the belief that a better understanding of student conceptions –
both in general and for specific domains – is essential for
designing instruction.
Sherin, Krakowski & Lee, 2011, p. 195
• Reinforces the notion that teachers’ use of STeLLA
strategies in classroom settings (as distinct from
interviews) contributes to students’ conceptual
understanding.
• Intermediate conceptual constructions can be thought of
as helpful steps along a learning progression building
deep scientific understanding.