Download Released Items from the ATLAST Plate Tectonics Teacher Assessment

Released Items from the ATLAST Plate Tectonics Teacher Assessment
Horizon Research, Inc. (HRI) developed the ATLAST Plate Tectonics Teacher Assessment as
part of a larger study. The project—Assessing Teacher Learning About Science Teaching
(ATLAST)—was funded by the National Science Foundation under Grant no. EHR-0335328.
Information about the ATLAST project is available at HRI’s ATLAST website:
http://www.horizon-research.com/atlast.
This document contains the plate tectonics teacher items that were developed during the process
of creating the ATLAST Plate Tectonics Teacher Assessment, but were not chosen to be on the
final assessment. The items were developed through a months-long iterative process that
included cognitive interviews with middle grades science teachers, review by a panel of three
content experts (individuals with a Ph.D. in geology), and field testing with a large sample of
science teachers. To learn more about the item development process, please see the ATLAST
Plate Tectonics Teacher Assessment User Manual, which can be found at the ATLAST website.
Content Assessed by the Items
All of the items measure understanding of the idea that
The outer portion of Earth—including both the continents and the seafloor beneath the oceans—consists of
huge plates of solid rock. The plates move very slowly (a few centimeters per year). Plate movement
causes abutting plates to interact with one another. Interactions between plates result in events and features
that are observable on Earth’s surface (e.g., earthquakes, volcanoes and mountain ranges); these typically
occur along boundaries between plates.1
In addition, the content domain was specified by “unpacking” this idea into 10 “sub-ideas,”
which are shown in Table 1. Each of the released assessment items included addresses one or
two specific sub-ideas.
Content Levels of Items
In addition to each item addressing specific sub-idea(s) in the domain of plate tectonics, each
item addresses the sub-idea(s) at one of three content levels:
1. knowledge of science content (Level 1 items);
2. using content knowledge to analyze/diagnose student thinking (Level 2 items); and
3. using content knowledge to make instructional decisions (Level 3 items).
All of the items assess knowledge of science content, but “Level 1” items are the most basic type
of question; they attempt to isolate disciplinary content knowledge from a teacher’s ability to
apply the knowledge in making instructional decisions.
“Level 2” items require teachers to apply their content knowledge in analyzing or diagnosing a
sample of student thinking. In these items, more than one of the answer choices includes a
correct physics statement. Therefore, a teacher must understand the science content in order to
1
Modified from: The Physical Setting: Processes that Shape the Earth: Grades 6-8: #11-13; 4C/M11, 4C/M12 and
4C/M13. American Association for the Advancement of Science/Project 2061. (2008). Benchmarks for Science
Literacy. Retrieved from http://www.project2061.org/publications/bsl/online/index.php
answer Level 2 items correctly, but s/he must also determine which answer choice is relevant to
the thinking expressed by the student.
“Level 3” items ask teachers to apply their content knowledge in choosing among instructional
moves. Teachers must evaluate the physical scenario, the student’s thinking in relation to the
physical scenario, and then evaluate each instructional choice. As with Level 2 items, more than
one answer choice has a correct physics statement, but only one has a correct physics statement
and is relevant to the instructional context.
Table 1
Plate Tectonics Content Domain
Idea: The outer portion of Earth—including both the continents and the seafloor beneath the oceans—
consists of huge plates of solid rock. The plates move very slowly (a few centimeters per year).
Plate movement causes abutting plates to interact with one another. Interactions between plates
result in events and features that are observable on Earth’s surface (e.g., earthquakes, volcanoes
and mountain ranges); these typically occur along boundaries between plates.
Sub-ideas:
A. The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
B. Earth’s plates (the lithosphere or lithospheric plate) are cold (relative to deeper portions of
Earth), strong and brittle and average about 100 kilometers in thickness. Beneath the lithosphere
is an almost entirely solid (~99%) layer of Earth (the asthenosphere) which is hot, weak and
plastic and extends from the base of the lithosphere to a depth of about 350 kilometers.
C. The plates that make up Earth’s surface are constantly moving and changing.
D. Plate motions are driven by a combination of Earth's heat and gravitational forces. The
consensus among geologists is that “slab pull,” the sinking of oceanic plates at subduction zones
(because that rock is old and relatively cold (dense)) is the primary driving force behind plate
tectonics. Ridge push (the pushing forces exerted by elevated and relatively hot rock at midocean ridges) is minor as is the traction along the bottoms of plates due to convection in the
mantle.
E. Since the supercontinent Pangaea split up about 200 million years ago, the shapes of continents
have been somewhat modified, mostly by erosion, sea level changes, and mountain-building;
this is why the present-day "fit" of the continents is less than perfect.
F. Plate motion causes abutting plates to interact with one another along their boundaries resulting
in observable geologic features and events.
G. The occurrence of features and/or events at locations distant from plate boundaries are for
reasons other than plate interactions (some volcanoes occur distant from plate boundaries as a
result of hot spots)]
H. The rock that makes up plates is slowly being formed at some plate boundaries and returned to
Earth’s interior at other plate boundaries. This means that Earth is not changing in size.
I. The part of a plate with ocean floor along its boundary is always subducted beneath a plate with
a continent along its boundary. Continental material is not subducted because of its low density.
If continents on two separate plates are in contact and being pushed together, the continental
rocks are forced upward forming mountain ranges rather than being completely subducted into
Earth’s interior. If two plates without continents are in contact and being pushed together, the
colder/denser plate subducts beneath the other.
J. Old ocean floor rocks return by subduction into Earth’s interior. Hence, ocean floor rocks are
relatively young. Most continental rocks stay at Earth’s surface because of their low density
(although sediment eroded from the continents is carried to the oceans and can be subducted
along with oceanic lithosphere). Hence, the age of some continental rock is quite old.
Field Test Response Data
All of the items include the p-values (proportion answering correctly) and distribution of
responses from a field test of the items. A pool of 60 plate tectonics teacher items, including all
of the items in this document, was distributed over three forms for the field test, with 15 items
common to each form. Just over 500 science teachers across the nation responded to each form.
Each field test group included roughly one-fifth high school earth science teachers to ensure an
adequate distribution of levels of teacher knowledge in the sample. The remaining respondents
were middle grades science teachers.
Item ID: PT-RE01
Key: C
P-value: 0.91
Percent Responding:
A
B
C
D
5%
1%
91%
3%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 1 – Knowledge of science content
When asked to draw a diagram of what Earth’s plates look like if there were no water on the planet,
a student draws this diagram.
What does this diagram indicate about this student’s thinking about Earth’s plates?
A.
B.
C.
D.
The student correctly thinks Earth’s plates have very large spaces between them.
The student correctly thinks that there are no plates beneath Earth’s oceans.
The student incorrectly thinks Earth’s plates have very large spaces between them.
The student incorrectly thinks Earth’s plates have never moved.
Item ID: PT-RE02
Key: C
P-value: 0.87
Percent Responding:
A
B
C
D
5%
8%
87%
0%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 1 – Knowledge of science content
A teacher asks her students to draw and label a diagram that represents Earth’s plates and their
boundaries. Which one of the following diagrams is the most accurate?
A.
Earth’s plates
C.
Earth’s plates
Ocean water
D.
B.
Earth’s plates
Mag
ma
Earth’s plate
Item ID: PT-RE03
Key: B
P-value: 0.92
Percent Responding:
A
B
C
D
1%
92%
2%
5%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
While discussing movement of plates, students examine a map of the Atlantic Ocean area that
shows major plates and their directions of movement. A student asks,
“I understand about large plates moving, but what happens to small islands?
They don’t move, do they?”
Which one of the following is the best assessment of what the student needs to learn about the
movement of islands and plates?
A.
B.
C.
D.
All small islands float in the ocean and can move easily.
All solid material (rock) on Earth’s surface, including islands, is part of a moving plate.
The islands don’t move because they all are at plate boundaries where nothing is moving.
The islands move because they are small plates on top of larger moving plates.
Item ID: PT-RE04
Key: B
P-value: 0.23
Percent Responding:
A
B
C
D
42%
23%
25%
10%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
A teacher has students draw a diagram of plates moving away from each other. One of his students
draws the following diagram:
Which one of the following is the best assessment of this student’s understanding of what happens
at this type of plate boundary?
A. The student’s understanding is incomplete; the area labeled “ocean” in the drawing should be
labeled “magma.”
B. The student’s understanding is incomplete; even though the plates are moving away from each
other, the edges of the two plates should still be touching.
C. The student’s understanding is incomplete; the area labeled “ocean” in the drawing should
show a deep sea trench.
D. The student seems to have a correct understanding of what happens at this type of boundary.
Item ID: PT-RE05
Key: B
P-value: 0.58
Percent Responding:
A
B
C
D
6%
58%
27%
9%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
Which one of the following activities would best help students understand the properties and
structure of the outer portion of Earth?
A.
B.
C.
D.
Have students cut an apple in half and compare the skin to plate material.
Have students gently crack a hard-boiled egg and compare the cracked shell to the plates.
Have students float pieces of cardboard on water and compare the cardboard to plate material.
Have students assemble a jigsaw puzzle to show that many of the continents “fit” together.
Item ID: PT-RE06
Key: A
P-value: 0.79
Percent Responding:
A
B
C
D
79%
3%
13%
4%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
At the beginning of a unit on plate tectonics, a teacher asks her students for their ideas about plates.
One student says,
“There are seven plates separated by the ocean.”
Based on this student’s response, which one of the following should the teacher do next to further
this student’s understanding of Earth’s plates?
A. Use a map to show students that plates touch other plates at all of their edges.
B. Have students investigate the density of different objects to understand why plates float on
water.
C. Explain why continents are a good way to tell where all the plates are located.
D. Model for students the plastic nature of the rock just beneath the outer layer of Earth.
Item ID: PT-RE07
Key: B
P-value: 0.88
Percent Responding:
A
B
C
D
5%
88%
4%
3%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
At the beginning of a unit on plate tectonics, a teacher asks her students to describe the outer layer
of Earth. One student says,
“The outer layer of Earth is like the shell of a hard-boiled egg. It is one solid
layer that could break.”
What idea does this student seem to be missing?
A. The outer layer of Earth is not entirely solid; there are ocean-sized, magma-filled gaps between
the plates.
B. The outer layer of Earth is broken up into sections called plates.
C. The outer portion of Earth is one solid layer, but it is not brittle; it is weak and plastic.
D. The outer layer of Earth extends half-way to Earth’s center, while the egg shell is much thinner
relative to the whole egg.
Item ID: PT-RE08
Key: D
P-value: 0.57
Percent Responding:
A
B
C
D
2%
31%
10%
57%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
When asked to draw a diagram of what Earth’s plates would look like if there were no water on the
planet, a student draws this diagram.
Based on the drawing, which one of the following is the best assessment of this student’s
understanding of Earth’s plates?
A. The student understands that Earth’s surface is broken up into plates, but does not understand
that they move very slowly.
B. The student understands that Earth’s plates include the continents, but does not understand that
plates are also found under the oceans.
C. The student understands that Earth’s plates vary in size and shape, but does not understand that
new plate material is formed at spreading centers.
D. The student understands that Earth’s surface is covered by about a dozen large plates, but does
not understand that Earth’s plates abut one another.
Item ID: PT-RE09
Key: A
P-value: 0.46
Percent Responding:
A
B
C
D
46%
6%
6%
42%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
While discussing the movement of plates, students examine a map of the Atlantic Ocean area that
shows the major plates and their directions of movement. A student asks,
“I understand about large plates moving, but how do small islands move?”
Which one of the following is a concept that this student needs to know in order to answer her own
question?
A. All solid rock on Earth’s surface is part of a moving plate.
B. Islands move because they are small plates on top of larger moving plates.
C. Oceanic plates move underneath continental plates because of differences between their
densities.
D. Volcanic islands can form as plates move toward one another or in the interior of plates as a
result of hot spots.
Item ID: PT-RE10
Key: A
P-value: 0.56
Percent Responding:
A
B
C
D
56%
37%
3%
4%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 3 – Using content knowledge to make instructional decisions
A middle school teacher is conducting a lesson on plate movement where students use the apparatus
shown below. In using this apparatus, continents are created out of clay and placed onto two belts
that can move. Students twist a pair of knobs to make the belts rotate toward one another or away
from one another.
Moving Continents Model
Before
After
Models in science can illustrate difficult concepts, but may also introduce or reinforce incorrect or
incomplete student ideas.
With the model shown above, which one of the following is an INCORRECT idea about Earth’s
plates and/or their movement that could be introduced or reinforced with this activity?
A.
B.
C.
D.
A continent is a plate.
All plates move in the same direction and at the same speed.
Earthquakes caused the plates to break apart.
The upper portions of some of Earth’s plates contain the continents.
Item ID: PT-RE11
Key: A
P-value: 0.79
Percent Responding:
A
B
C
D
79%
16%
2%
3%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 3 – Using content knowledge to make instructional decisions
During a lesson on Earth’s plates, the teacher realizes that some of her students believe that each
plate is the same shape as one of the continents. For example, some students believe that the
African plate is the same shape as the continent of Africa. What should the teacher do in response
to this realization?
A. Tell students that the plate is not the same shape as the continent and that plate material usually
extends beyond the continent and under the ocean.
B. Show students that plates are well below Earth’s surface and have little relationship to the
continents.
C. Explain to students that while they are the same shape, continents are much thinner than plates.
D. Affirm that the students seem to have a correct understanding.
Item ID: PT-RE12
Key: C
P-value: 0.93
Percent Responding:
A
B
C
D
1%
2%
93%
4%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 3 – Using content knowledge to make instructional decisions
A teacher asks his students to describe what happens when two plates move away from each other.
In answering, one student puts his hands together with his fingers touching, then slowly moves
them away from each other until they are a few inches apart.
At the same time, the student says,
“The plates move apart like this.”
While the student is correctly showing two objects moving away from each other, which one of the
following would be best for the teacher to do next to assess the student’s understanding?
A. The teacher should ask the student to describe how non-volcanic mountains can be formed in
this situation.
B. The teacher should ask the student about the conditions under which a deep-sea trench would
form.
C. The teacher should ask what is happening in the space that is created between the student’s
hands.
D. The student’s understanding seems complete; have the student model what happens when
plates move toward each other.
Item ID: PT-RE13
Key: A
P-value: 0.37
Percent Responding:
A
B
C
D
37%
30%
15%
17%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 3 – Using content knowledge to make instructional decisions
A teacher instructs her students to draw a cross-sectional diagram of what happens at a plate
boundary where two plates are moving away from each other. One of the students draws the
following diagram.
Which one of the following would NOT be a good question to ask this student in order to better
assess his understanding of what happens when two plates move away from each other?
A.
B.
C.
D.
“Where would the deep sea trench be in your diagram?”
“How did the water get in between the plates?”
“Were the plates touching before they moved away from each other?”
“Where is new plate material formed?”
Item ID: PT-RE14
Key: D
P-value: 0.35
Percent Responding:
A
B
C
D
11%
36%
17%
35%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 3 – Using content knowledge to make instructional decisions
A teacher instructs her students to draw a cross-sectional diagram of what happens at a plate
boundary where two plates are moving away from each other. One of the students draws the
following diagram.
Most of the students in the class drew something similar. Which one of the following would NOT
help the teacher move the students forward in their understanding of what happens when two plates
move away from each other?
A.
B.
C.
D.
Show a computer animation of the formation of mid-ocean ridges.
Show a map of Earth with all plate boundaries.
Explain how plate movement is associated with the formation of new rock.
Have the students investigate deep-sea trench formation.
Item ID: PT-RE55
Key: C
P-value: 0.87
Percent Responding:
A
B
C
D
9%
0%
87%
4%
Primary Sub-Idea(s) Assessed:
A: The solid outer portion of Earth consists of separate plates of almost entirely solid rock.
Content Level: 3 – Using content knowledge to make instructional decisions
When asked to draw a diagram of what Earth’s plates look like, a student draws this diagram:
Based on the diagram, what question should the teacher ask to better assess the student’s thinking
about Earth’s plates?
A.
B.
C.
D.
“In which direction are the plates moving?”
“How thick are the plates?”
“What is between the plates in your diagram?”
“Where were the plates ten million years ago?”
Item ID: PT-RE15
Key: C
P-value: 0.47
Percent Responding:
A
B
C
D
2%
12%
47%
39%
Primary Sub-Idea(s) Assessed:
B: Earth’s plates (the lithosphere or lithospheric plate) are cold (relative to deeper portions of Earth), strong and
brittle and average about 100 kilometers in thickness. Beneath the lithosphere is an almost entirely solid
(~99%) layer of Earth (the asthenosphere) which is hot, weak and plastic and extends from the base of the
lithosphere to a depth of about 350 kilometers.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
A teacher wants to help her students understand the physical properties of Earth’s plates and the
material directly under the plates. Which one of the following models most closely represents the
physical properties of Earth’s plates and the underlying material?
A.
B.
C.
D.
Rubber mats sitting on a block of wood
Pieces of wood floating on water
Crackers sitting on solid Jello
Marshmellows floating on syrup
Item ID: PT-RE16
Key: B
P-value: 0.93
Percent Responding:
A
B
C
D
1%
93%
6%
1%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 1 – Knowledge of science content
A teacher shows her students the following diagram of two landmasses as they appear today
(bottom picture), and as they were a long time ago (top picture). She asks them to explain what
happened between the top and bottom pictures.
Which one of the following would be an acceptable student answer?
A.
B.
C.
D.
Water eroded a large canyon between the two landmasses.
The landmass split apart as plates moved away from each other.
A series of earthquakes along the plate boundary forced the landmasses apart.
The ocean currents slowly moved the landmasses away from each other.
Item ID: PT-RE17
Key: D
P-value: 0.86
Percent Responding:
A
B
C
D
1%
5%
8%
86%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 1 – Knowledge of science content
A teacher holds a class discussion about plate motion. The following is a portion of that
discussion.
Joseph: I’d say that plates move at a snail’s pace – very slowly.
Amman: Joseph is correct in that plates move slowly, but you can see a
snail moving and you can’t see a plate moving, so I’d say a snail’s
pace is too fast. I think plates move so slowly that it would take
millions of years before you could ever tell that a plate had
moved.
Stephanie:
Amman is right about the snail’s pace being too fast, but I
think that plates move very fast during earthquakes and then they
don’t move at all for a very long time.
Lucinda: I think plates move a few centimeters every year, and I disagree
with Amman that it takes millions of years to tell that a plate has
moved. Geologists can measure how far a plate has moved in just
one year.
Based solely on what the students say, which one seems to have the best understanding of plate
motion?
A.
B.
C.
D.
Joseph
Amman
Stephanie
Lucinda
Item ID: PT-RE18
Key: B
P-value: 0.95
Percent Responding:
A
B
C
D
1%
95%
3%
1%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 1 – Knowledge of science content
While leading a discussion about Earth’s plates, a student says,
“The plates can’t crash together because they are all moving in the same
direction—from East to West, at roughly the same speed.”
Which one of the following is the best assessment of this student’s statement?
A. The student is incorrect; Earth’s plates move in the same direction but at different speeds, so
the slower plates get hit from behind.
B. The student is incorrect; Earth’s plates are not all moving in the same direction. Some plates
are moving away from other plates while others are moving toward other plates.
C. The student is incorrect; Earth’s plates are all moving in the same direction, but their
movement is aligned with Earth’s magnetic field.
D. The student is correct; Earth’s plates do move in the same direction at the same speed.
Item ID: PT-RE19
Key: D
P-value: 0.42
Percent Responding:
A
B
C
D
27%
28%
4%
42%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 1 – Knowledge of science content
During a class discussion about Earth’s plates, a student says,
“I think that two plates can join together to form one plate and one plate can
split to form two plates.”
Which one of the following is the best assessment of this student’s statement?
A.
B.
C.
D.
The student’s statement is incorrect; plates do not join together or split apart.
Part of the student statement is incorrect; plates can split apart but they do not join together.
Part of the student statement is incorrect; plates can join together but they do not split apart.
The student’s statement is correct; plates can join together and split apart.
Item ID: PT-RE20
Key: B
P-value: 0.76
Percent Responding:
A
B
C
D
12%
76%
11%
1%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
A teacher shows her students the following diagram of two present-day landmasses as they were a
long time ago (top picture), and as they appear today (bottom picture).
She asks them to explain what happened between the top and bottom pictures. A student says,
“The continents moved apart when earthquakes pushed them away from each
other.”
What does this answer indicate about the student’s thinking?
A. The student incorrectly thinks that continents and plates are the same thing.
B. The student incorrectly thinks that large-scale continental movement is caused by earthquakes.
C. The student correctly thinks that earthquakes result in large-scale continental movement, but
failed to mention the formation of a mid-ocean ridge.
D. The student is correct in her thinking.
Item ID: PT-RE21
Key: D
P-value: 0.90
Percent Responding:
A
B
C
D
1%
3%
7%
90%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
While leading a discussion on Earth’s plates, a student says,
“The plates move from east to west, at roughly the same speed.”
What is wrong with this student’s statement?
A.
B.
C.
D.
The student doesn’t realize that plates are stationary.
The student doesn’t realize that plates move back and forth but do not go very far.
The student doesn’t realize that plates move in different directions but at the same speeds.
The student doesn’t realize that plates move in different directions and at different speeds.
Item ID: PT-RE22
Key: B
P-value: 0.42
Percent Responding:
A
B
C
D
27%
42%
4%
27%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
During a class discussion about the supercontinent Pangaea, one student says,
“A long time ago, Pangaea broke up and the continents floated away from each
other. Now the continents are all spread out all over Earth.”
Which one of the following is the best assessment of this student’s response?
A. The student knows that Pangaea broke up, but does not understand that the continents are still
moving today.
B. The student knows that the continents have moved over time, but does not understand that the
continents moved only as the plates moved.
C. The student knows that the breakup of Pangaea took place a long time ago, but does not
understand that new plate material has been formed since then.
D. The student knows the continents can move away from each other, but does not understand that
they can move toward each other too.
Item ID: PT-RE23
Key: C
P-value: 0.89
Percent Responding:
A
B
C
D
6%
3%
89%
2%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
During a unit on plate tectonics, a teacher asks her students to talk about the relationship between
Earth’s plates and continents. One student says,
“Earth’s plates move, but the continents stay in pretty much the same place.
The continents are above the plates.”
Based on this statement, which one of the following is the best assessment of this student’s thinking
about Earth’s plates and continents?
A. The student does not understand that Earth’s plates and continents can move away from each
other, toward each other, or alongside each other.
B. The student does not understand that the size and shape of Earth’s plates and continents can
change over time.
C. The student does not understand that continents are part of plates and therefore move as Earth’s
plates move.
D. The student does not understand that continental plate material is less dense than oceanic plate
material.
Item ID: PT-RE24
Key: A
P-value: 0.41
Percent Responding:
A
B
C
D
41%
27%
24%
8%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
While monitoring students working in groups, a teacher overhears a student say:
“Pangaea broke apart and now there are about a dozen plates. I bet if we could
time travel into the future, we’d see a lot more plates and continents than there
are now.”
Which one of the following is the best assessment of this student’s thinking?
A. The student understands that plates can split apart, but does not understand that plates can also
join together.
B. The student understands that Pangaea broke up, but does not understand that continents are the
top part of some plates.
C. The student understands approximately how many plates cover Earth’s surface, but does not
understand that continents move only as the plate moves.
D. The student seems to have a correct understanding; Earth’s plates will continue to split into
smaller and smaller plates.
Item ID: PT-RE25
Key: D
P-value: 0.49
Percent Responding:
A
B
C
D
13%
27%
11%
49%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 3 – Using content knowledge to make instructional decisions
In a discussion about plate movement, one student says,
“The plates move so slowly that nothing really happens.”
Most of the students agree with this student’s statement. Which one of the following would NOT
help the teacher move the students forward in their understanding about plates and plate motion?
A. Discuss how in the region between India and Asia, two plates are fusing and a large mountain
range can be found.
B. Show students a map that indicates the areas of the world that are volcanically active and
superimpose on it a plate boundary map.
C. Explain to students how a rift valley is forming in eastern Africa.
D. Use measurements made with satellites to show students how slowly the plates are moving.
Item ID: PT-RE26
Key: A
P-value: 0.53
Percent Responding:
A
B
C
D
53%
2%
8%
37%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 3 – Using content knowledge to make instructional decisions
In a discussion about plate movement, one student says,
“The plates move so slowly that nothing really happens.”
Most of the students agree with this student’s statement. Which one of the following would be
good for the teacher to do next in order to move the students forward in their understanding about
plates and plate motion?
A. Discuss how Africa and South America were once joined and then split as a result of plate
movement.
B. Have students investigate data showing that plates are deep underneath the continents and do
not affect Earth’s surface.
C. Explain to students that plate movement is so slow that one person cannot collect evidence for
plate movement within a lifetime.
D. Use measurements made with satellites to show students how slowly the plates are moving.
Item ID: PT-RE27
Key: B
P-value: 0.68
Percent Responding:
A
B
C
D
18%
68%
12%
2%
Primary Sub-Idea(s) Assessed:
C: The plates that make up Earth’s surface are constantly moving and changing.
Content Level: 3 – Using content knowledge to make instructional decisions
A teacher shows her students the following diagram of a landmass as it was long ago and today.
She asks the students what they think happened in the time between the two pictures.
One student says,
“I think water eroded a giant canyon in the landmass and then the ocean filled it
in.”
Most of the students agree with this student’s statement. Which one of the following, if any, should
the teacher do next to move the students’ thinking forward about what happened?
A. Show students a computer animation of activity along subduction zones to demonstrate how
continental material can be removed from Earth’s surface.
B. Have students pencil in the outlines of the two “today” landmasses onto the “long ago”
landmass and then ask students whether they still believe erosion played a role in the situation.
C. Have students watch a video on the power of earthquakes and their effect on Earth’s surface to
help them recognize that earthquakes caused the landmass to split.
D. The students seem to have a correct understanding of what happened.
Item ID: PT-RE28
Key: A
P-value: 0.04
Percent Responding:
A
B
C
D
4%
89%
4%
2%
Primary Sub-Idea(s) Assessed:
D: Plate motions are driven by a combination of Earth's heat and gravitational forces. The consensus among
geologists is that slab pull, the sinking of oceanic plates at subduction zones (because that rock is old and
relatively cold (dense)) is the primary driving force behind plate tectonics. Ridge push (the pushing forces
exerted by elevated and relatively hot rock at mid-ocean ridges) is minor as is the traction along the bottoms
of plates due to convection in the mantle.
Content Level: 1 – Knowledge of science content
In a unit on plate tectonics, students ask the teacher about the cause of plate movement. Which one
of the following responses is the most accurate explanation of the primary cause of plate
movement?
A. The denser portion of a plate sinks into Earth’s interior, slowly pulling the rest of the plate with
it.
B. Convection currents within the mantle move the plates.
C. The elevated mid-ocean ridge pushes a plate toward a subduction zone.
D. Dense continental rocks push plates into Earth’s interior.
Item ID: PT-RE29
Key: D
P-value: 0.08
Percent Responding:
A
B
C
D
18%
70%
4%
8%
Primary Sub-Idea(s) Assessed:
D: Plate motions are driven by a combination of Earth's heat and gravitational forces. The consensus among
geologists is that slab pull, the sinking of oceanic plates at subduction zones (because that rock is old and
relatively cold (dense)) is the primary driving force behind plate tectonics. Ridge push (the pushing forces
exerted by elevated and relatively hot rock at mid-ocean ridges) is minor as is the traction along the bottoms
of plates due to convection in the mantle.
Content Level: 1 – Knowledge of science content
In a unit on plate tectonics, a student asks her teacher what causes Earth’s plates to move. Which
one of the following responses is the most accurate?
A. “Convection currents in the mantle cause plates to move from subduction zones toward midocean ridges.”
B. “The circular movement of material in the mantle by convection is the major force that propels
the plates.”
C. “The sinking plate at a subduction zone pulls the rest of the plate behind it because the sinking
plate is hotter and less dense than its neighboring plate(s).”
D. “The sinking plate at a subduction zone pulls the rest of the plate behind it because the sinking
plate is colder and more dense than its neighboring plate(s).”
Item ID: PT-RE30
Key: A
P-value: 0.74
Percent Responding:
A
B
C
D
74%
16%
1%
9%
Primary Sub-Idea(s) Assessed:
E: Since the supercontinent Pangaea split up about 200 million years ago, the shapes of continents have been
somewhat modified, mostly by erosion, sea level changes, and mountain-building; this is why the present-day
fit of the continents is less than perfect.
Content Level: 1 – Knowledge of science content
A student noticed that the continents that made up the supercontinent Pangaea 200 million years
ago do NOT appear to be able to fit together perfectly today (like pieces of a jigsaw puzzle).
Which one of the following is most responsible for this imperfect fit?
A.
B.
C.
D.
Erosion and sea level changes
Convergence of plates and formation of subduction zones
Hot spots and formation of volcanoes
Divergence and seafloor spreading
Item ID: PT-RE31
Key: C
P-value: 0.80
Percent Responding:
A
B
C
D
9%
2%
80%
9%
Primary Sub-Idea(s) Assessed:
E: Since the supercontinent Pangaea split up about 200 million years ago, the shapes of continents have been
somewhat modified, mostly by erosion, sea level changes, and mountain-building; this is why the present-day
fit of the continents is less than perfect.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
During a class activity that involves students cutting continents out of a world map and then
reassembling Pangaea, two students become involved in a discussion about why the continents do
not fit together perfectly.
Carlos: I think the continents don’t fit together perfectly because every time the
continents run into each other, some stuff breaks off and falls into the
gaps.
Jake:
Well, I think it’s because the continents were never really joined. It just
looks like they were.
Which one of the following is the best explanation for why the continents do not fit together
perfectly?
A. Carlos is essentially correct; when continents collide, material can break off and fall into the
gaps between the plates.
B. Jake is essentially correct; the fact that some continents appear to fit together perfectly like a
jigsaw puzzle is just a coincidence.
C. Both students are incorrect; the continents do not fit together because their shapes have
changed some as a result of erosion and changes in sea-level.
D. Both students are incorrect; the continents do not fit together because rock material is removed
from the edges of continents by subduction.
Item ID: PT-RE32
Key: D
P-value: 0.63
Percent Responding:
A
B
C
D
15%
13%
9%
63%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 1 – Knowledge of science content
A class is generating a list of events associated with specific types of plate movement. Which one
of the following should be included on the list?
A.
B.
C.
D.
The formation of a deep sea trench where a plate moves away from another plate
The formation of a mid-ocean ridge where a plate moves toward another plate
The formation of a rift valley where a plate moves alongside another plate
The formation of a volcanic mountain near the boundary where one plate moves beneath
another plate
Item ID: PT-RE33
Key: B
P-value: 0.84
Percent Responding:
A
B
C
D
10%
84%
2%
4%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 1 – Knowledge of science content
On a relief map of the world, a class of students notices part of an ocean basin that has relatively
few geologic features, such as volcanoes, mountain ranges, ocean trenches, or mid-ocean ridges.
When the teacher asks why those features are scarce there, a student says,
“The plates stopped moving after the split-up of Pangaea, so there will not be
many new features until the plates start to move again.”
Which one of the following is the best assessment of this student’s thinking?
A. The student is incorrect in thinking that the plates stopped moving, and incorrect in relating
features to plate motion.
B. The student is incorrect in thinking that the plates stopped moving, but correct in thinking that
features result from plate motion.
C. The student is correct in thinking that the plates are not moving, but incorrect in thinking that
they will start moving again.
D. The student has a correct understanding of the situation described.
Item ID: PT-RE34
Key: D
P-value: 0.41
Percent Responding:
A
B
C
D
7%
41%
41%
11%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
G: The occurrence of features and/or events at locations distant from plate boundaries are for reasons other than
plate interactions (some volcanoes occur distant from plate boundaries as a result of hot spots).
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
During a lesson on the formation of volcanoes, a teacher asks his students for possible explanations
for a volcano. Which one of the following is NOT a correct explanation?
A.
B.
C.
D.
A volcano forms as a result of a hot spot causing rock to melt.
A volcano forms as a result of ocean floor subducting under a continent.
A volcano forms as a result of one plate splitting to form two separate plates.
A volcano forms as a result of two plates with continents colliding.
Item ID: PT-RE35
Key: B
P-value: 0.83
Percent Responding:
A
B
C
D
4%
83%
1%
11%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
While studying the impact of plate tectonics on humans, a teacher gives his students an assignment
to argue that a particular location is either hazard-rich or hazard-poor. Which one of these student
statements demonstrates the best understanding of the hazards related to plate tectonics?
A. “Hazard-rich areas are found near plate boundaries where plates move away from each other—
volcanic eruptions occur there, although earthquakes do not.”
B. “Hazard-rich areas are found near plate boundaries where plates move toward each other—both
earthquakes and volcanoes occur there.”
C. “Hazard-poor areas are found near plate boundaries where plates move alongside each other—
no earthquakes or volcanoes occur there.”
D. “Areas cannot be classified as either hazard-rich or hazard-poor because earthquakes and
volcanoes can occur just about anywhere.”
Item ID: PT-RE36
Key: C
P-value: 0.55
Percent Responding:
A
B
C
D
2%
20%
55%
23%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
On a relief map of an ocean basin, a class notices part of the ocean basin has relatively few geologic
features, such as volcanoes, mountain ranges, ocean trenches, or mid-ocean ridges. When the
teacher asks why those features are scarce there, a student says,
“It’s probably because the plate isn’t moving right there. If the plate was
moving there, you would probably see some stuff, like volcanoes or mountain
ranges.”
Which one of the following is the best assessment of this student’s understanding of the situation?
A. The student understands that plates can change their speed, but does not understand that they
can also change their direction.
B. The student understands that geologic features commonly occur together, but does not
understand that they can occur far away from plate boundaries.
C. The student understands that geologic features are related to plate motion, but does not
understand that such features are uncommon away from plate boundaries.
D. The student seems to have a correct understanding of the situation described.
Item ID: PT-RE37
Key: D
P-value: 0.63
Percent Responding:
A
B
C
D
3%
18%
16%
63%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
A teacher shows her students a map that plots the occurrence of earthquakes around the world. She
then asks her students if there is any reason for the pattern they are seeing on the map or if it is just
coincidence. One student says,
“There is a reason for the pattern. I think that most of these earthquakes are
happening near plate boundaries.”
Which one of the following is the best assessment of this student’s understanding of patterns of
earthquake occurrences?
A. The student understands that earthquakes occur in patterns, but does not understand that the
pattern is the same as that of volcanic eruptions.
B. The student understands that earthquakes occur near plate boundaries, but does not understand
that earthquakes can happen far from boundaries as well.
C. The student understands that earthquakes occur in patterns, but does not understand that
earthquakes are ultimately the result of plate motion.
D. The student seems to have a correct understanding of patterns of earthquake occurrences.
Item ID: PT-RE38
Key: C
P-value: 0.37
Percent Responding:
A
B
C
D
37%
24%
37%
3%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
While studying interactions between plates, a teacher asks his students why earthquakes are
common in some areas and not others. One student says,
“Earthquakes are common at the edge of a plate, like in California, because
that’s where the plate meets the ocean.”
Based on this student’s statement, which one of the following ideas, if any, is the student missing?
A.
B.
C.
D.
Earthquakes can occur at all plate boundaries.
Earthquakes can also occur in areas that are not near the edges of plates.
Earth’s plates are also under the oceans.
The student’s statement is accurate and complete.
Item ID: PT-RE39
Key: C
P-value: 0.74
Percent Responding:
A
B
C
D
3%
9%
74%
14%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 3 – Using content knowledge to make instructional decisions
In a pretest for a unit on plate tectonics, a teacher asks her students to draw a picture of Earth’s
plates. In reviewing the students’ responses, the teacher notices that many students draw plates that
correspond to the edges of continents, with the plate boundaries separated by large water-filled
gaps.
Which one of the following maps would be useful in helping move students’ thinking forward
about the boundaries of Earth’s plates?
A.
B.
C.
D.
A map that shows the locations of volcanoes on continents
A map that shows the location of the continents
A map that shows the occurrences of earthquakes and volcanic eruptions
A map that shows Pangaea
Item ID: PT-RE40
Key: D
P-value: 0.72
Percent Responding:
A
B
C
D
20%
3%
5%
72%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 3 – Using content knowledge to make instructional decisions
During a class discussion, a teacher asks a student to describe what happens when two continents
come together or collide as a result of two plates moving toward each other. The student replies,
“When the plates move toward each other there will be a lot of earthquakes.”
Which one of the following questions should the teacher pose to the student to assess the
completeness of his understanding of continental collisions?
A.
B.
C.
D.
“Under what other circumstances would you expect to find earthquakes?”
“How strong are the earthquakes that happen when two continents collide?”
“How does this type of plate motion cause rifting of continents and formation of rift valleys?”
“What happens to the continental material as the plates move toward each other?”
Item ID: PT-RE41
Key: D
P-value: 0.59
Percent Responding:
A
B
C
D
13%
23%
5%
59%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 3 – Using content knowledge to make instructional decisions
A teacher asks her students what they think happens as a result of Earth’s plates interacting with
each other. One student says,
“Earth’s plates move so slowly that nothing really happens.”
If most of the students agreed with this statement, which one of the following should the teacher do
next to move their thinking forward about plate interactions?
A. Have students investigate hot spot volcanoes and plot their locations on a world map that
includes plate boundaries.
B. Have students cut out pieces of paper representing the present-day continents and, by matching
the coastlines, reassemble Pangaea.
C. Have students create a bar graph that displays the relative strengths of earthquakes that have
occurred over the past 10 years.
D. Have students plot earthquake activity onto a world map that includes plate boundaries.
Item ID: PT-RE42
Key: D
P-value: 0.59
Percent Responding:
A
B
C
D
14%
8%
18%
59%
Primary Sub-Idea(s) Assessed:
F: Plate motion causes abutting plates to interact with one another along their boundaries resulting in observable
geologic features and events.
Content Level: 3 – Using content knowledge to make instructional decisions
A teacher asks her students what happens when two plates move toward each other. One student
says,
“The plates run into each other forming mountains.”
Based on this student’s statement, which one of the following would be a poor question to ask this
student if the teacher wants to further assess his understanding of what happens when two plates
move toward each other?
A.
B.
C.
D.
“Can anything else happen when the two plates move toward each other?”
“Do mountains always form in this situation?”
“What is at the edges of these two plates—continents or seafloor?”
“Can you describe how mountains form as a result of hot spots?”
Item ID: PT-RE43
Key: B
P-value: 0.59
Percent Responding:
A
B
C
D
22%
59%
18%
2%
Primary Sub-Idea(s) Assessed:
H: The rock that makes up plates is slowly being formed at some plate boundaries and returned to Earth’s interior
at other plate boundaries. This means that Earth is not changing in size.
Content Level: 1 – Knowledge of science content
A student describes how old rock material goes back into Earth’s interior at some plate boundaries,
but she does not discuss whether new rock material is formed. Which one of the following
statements correctly describes the formation of new rock material?
A. Volcanic eruptions create new rock material only where plates are moving toward each other.
B. Volcanic activity creates new rock material at plate boundaries where plates are moving away
from each other.
C. New rock material is added only to the tops of plates.
D. New rock material is no longer created by plate interactions.
Item ID: PT-RE44
Key: D
P-value: 0.87
Percent Responding:
A
B
C
D
1%
9%
3%
87%
Primary Sub-Idea(s) Assessed:
H: The rock that makes up plates is slowly being formed at some plate boundaries and returned to Earth’s interior
at other plate boundaries. This means that Earth is not changing in size.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
A teacher wants to see if her students can apply what they have learned about plate tectonics to the
overall size of Earth. She decides to start a class discussion by asking, “Does the size of Earth
change over time?” The following is a portion of that discussion.
Jamie: I know that new plate material is added to the edges of plates, so I
think that Earth is slowly getting larger over time.
David: I agree with Jamie that new plate material is being added to the edges
of plates, but I also think that erosion wears away other parts of plates
so that the amount of plate material stays the same. Earth is staying
the same size.
Jackie: The amount of new plate material that is being added to the edges of
plates is much less than the amount of plate material that goes back into
Earth’s interior when plates move toward one another, so I think Earth is
getting smaller over time.
Rachel: I agree with David that Earth is staying the same size, but I think it’s
because the amount of plate material that is added to the edges of
plates is about the same as the amount of old plate material that goes
back into Earth’s interior.
Which one of the following students has the best understanding of why the overall size of Earth is
changing or staying the same?
A.
B.
C.
D.
Jamie
David
Jackie
Rachel
Item ID: PT-RE45
Key: C
P-value: 0.93
Percent Responding:
A
B
C
D
1%
3%
93%
2%
Primary Sub-Idea(s) Assessed:
H: The rock that makes up plates is slowly being formed at some plate boundaries and returned to Earth’s interior
at other plate boundaries. This means that Earth is not changing in size.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
A student asks his teacher,
“Isn’t it true that Earth is very slowly getting bigger because of new rock being
added to Earth’s plates?”
Which one of the following is the best assessment of this student’s understanding of plate tectonics
relative to the size of Earth?
A. This student’s understanding is incorrect; Earth is not getting bigger because rock was added to
plates in the distant past, but not now.
B. This student’s understanding is incorrect; Earth is not getting bigger because the addition of
rock to existing plates is insignificant.
C. This student’s understanding is incorrect; Earth is not getting bigger because rock is also being
removed from plates.
D. This student seems to have a correct understanding of plate tectonics relative to the size of
Earth.
Item ID: PT-RE46
Key: C
P-value: 0.75
Percent Responding:
A
B
C
D
2%
9%
75%
13%
Primary Sub-Idea(s) Assessed:
H: The rock that makes up plates is slowly being formed at some plate boundaries and returned to Earth’s interior
at other plate boundaries. This means that Earth is not changing in size.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
During a plate tectonics unit, a student asks,
“I know that all rock isn’t EXACTLY the same age, but isn’t it OK to say that all
rock is about the same age – pretty old?”
Which one of the following is a concept that this student needs to know in order to answer his own
question?
A. Even though Earth’s plates are recycled, the rock that makes up the plates stays unchanged and
thus is very old and all about the same age.
B. Continental rock tends to stay at or near Earth’s surface because of its low density and is thus
very old.
C. New and thus young rock is continually forming where plates move away from each other.
D. Earth’s plates move so slowly that it takes hundreds of millions of years before rock is
subducted back into Earth.
Item ID: PT-RE47
Key: C
P-value: 0.63
Percent Responding:
A
B
C
D
4%
31%
63%
2%
Primary Sub-Idea(s) Assessed:
I: The part of a plate with ocean floor along its boundary is always subducted beneath a plate with a continent
along its boundary. Continental material is not subducted because of its low density. If continents on two
separate plates are in contact and being pushed together, the continental rocks are forced upward forming
mountain ranges rather than being completely subducted into Earth’s interior. If two plates without continents
are in contact and being pushed together, the colder/denser plate subducts beneath the other.
Content Level: 1 – Knowledge of science content
A middle school science class is studying the Himalayas, a mountain range located between India
and China. Which one of the following correctly explains the formation of the Himalayas?
A. The Himalayas are the result of volcanic activity that has built up volcanic mountains over a
long period of time.
B. The Himalayas are pushed up by the subduction of high-density continental material
underneath another plate.
C. The Himalayas are pushed up because the low-density continental rocks cannot be subducted.
D. The Himalayas are an area of continental material that has always been high.
Item ID: PT-RE48
Key: C
P-value: 0.75
Percent Responding:
A
B
C
D
8%
7%
75%
10%
Primary Sub-Idea(s) Assessed:
I: The part of a plate with ocean floor along its boundary is always subducted beneath a plate with a continent
along its boundary. Continental material is not subducted because of its low density. If continents on two
separate plates are in contact and being pushed together, the continental rocks are forced upward forming
mountain ranges rather than being completely subducted into Earth’s interior. If two plates without continents
are in contact and being pushed together, the colder/denser plate subducts beneath the other.
Content Level: 1 – Knowledge of science content
A teacher describes the arrangement of two plates (A and B) moving toward one another. Plate A
includes a continent at its edge next to Plate B, but Plate B does not include a continent. The
teacher asks the class what they would expect to happen in this situation.
Which one of the following answers is a correct student response?
A. The two plates would push together both moving upward, forming a range of non-volcanic
mountains.
B. Plate B would ride up and over the top of Plate A with the stacked plates resulting in
mountains.
C. Plate B would be subducted beneath Plate A forming a volcanic mountain range.
D. Plate A would be subducted beneath Plate B forming a deep-sea trench.
Item ID: PT-RE49
Key: A
P-value: 0.75
Percent Responding:
A
B
C
D
75%
12%
4%
9%
Primary Sub-Idea(s) Assessed:
I: The part of a plate with ocean floor along its boundary is always subducted beneath a plate with a continent
along its boundary. Continental material is not subducted because of its low density. If continents on two
separate plates are in contact and being pushed together, the continental rocks are forced upward forming
mountain ranges rather than being completely subducted into Earth’s interior. If two plates without continents
are in contact and being pushed together, the colder/denser plate subducts beneath the other.
Content Level: 1 – Knowledge of science content
A teacher is going to teach a lesson on what happens where two plates are moving toward one
another. The teacher wants to make sure she understands not only what happens, but why it
happens.
A diagram in a textbook shows two adjacent plates. One plate has oceanic material along its edge
where the two plates meet. The other plate includes continental material along the edge where the
two plates meet.
Which one of the following best explains what will happen as the plates move toward one another
and why?
A. The plate with oceanic material will subduct because it is denser than the plate with continental
material.
B. The plate with oceanic material will subduct because it is thinner than the plate with continental
material.
C. The plate with the older rock will subduct because older rock is relatively cold and denser.
D. Neither plate will subduct; both plates will push up to form a chain of mountains because the
plates bend and fold as they are forced together.
Item ID: PT-RE50
Key: A
P-value: 0.72
Percent Responding:
A
B
C
D
72%
13%
13%
2%
Primary Sub-Idea(s) Assessed:
I: The part of a plate with ocean floor along its boundary is always subducted beneath a plate with a continent
along its boundary. Continental material is not subducted because of its low density. If continents on two
separate plates are in contact and being pushed together, the continental rocks are forced upward forming
mountain ranges rather than being completely subducted into Earth’s interior. If two plates without continents
are in contact and being pushed together, the colder/denser plate subducts beneath the other.
Content Level: 1 – Knowledge of science content
A teacher is going to teach a lesson on what happens where two plates are moving toward one
another. The teacher wants to make sure she understands not only what happens, but why it
happens.
A diagram in a textbook shows two adjacent plates. One plate has oceanic material along its edge
where the two plates meet. The other plate includes continental material along the edge where the
two plates meet.
Which one of the following best explains what will happen as the plates move toward one another
and why?
A. The plate with oceanic material will subduct because it is denser than the plate with continental
material.
B. The plate with continental material will subduct because it is denser than the plate with oceanic
material.
C. The plate with oceanic material will subduct because it is thinner than the plate with continental
material.
D. The plate with continental material will subduct because it is thinner than the plate with oceanic
material.
Item ID: PT-RE51
Key: A
P-value: 0.75
Percent Responding:
A
B
C
D
75%
19%
4%
2%
Primary Sub-Idea(s) Assessed:
J: Old ocean floor rocks return by subduction into Earth’s interior. Hence, ocean floor rocks are relatively
young. Most continental rocks stay at Earth’s surface because of their low density (although sediment eroded
from the continents is carried to the oceans and can be subducted along with oceanic lithosphere). Hence, the
age of some continental rock is quite old.
Content Level: 1 – Knowledge of science content
A teacher is reviewing some background information in preparation for a lesson on plate
subduction. Which one of the following statements about subducting plates is a correct idea the
teacher could include in her lesson?
A. The subducting plate has a higher density than the overriding plate.
B. The subducting plate has a lower density than the overriding plate.
C. The densities of the two plates are the same, but the subducting plate is hotter than the
overriding plate.
D. The densities of the two plates are the same, but the subducting plate is colder than the
overriding plate.
Item ID: PT-RE52
Key: A
P-value: 0.59
Percent Responding:
A
B
C
D
59%
21%
6%
14%
Primary Sub-Idea(s) Assessed:
J: Old ocean floor rocks return by subduction into Earth’s interior. Hence, ocean floor rocks are relatively
young. Most continental rocks stay at Earth’s surface because of their low density (although sediment eroded
from the continents is carried to the oceans and can be subducted along with oceanic lithosphere). Hence, the
age of some continental rock is quite old.
Content Level: 1 – Knowledge of science content
A middle school student finds an earth science website that says,
The oldest ocean floor rocks are roughly 180 million years old, while the oldest continental
rocks are more than 20 times as old—about 4 billion years old.
The student shares this statement with her teacher and asks for an explanation. Which one of the
following is the correct explanation for the observation?
A. The rock that makes up the ocean floor is denser than the rock that makes up the continents,
and is continually recycled through the mantle.
B. There is likely to be some ocean floor rock that is as old as the continents, it’s just that
geologists are not able to study the ocean floor as thoroughly.
C. The statement is referring only to some continents; some continents are almost entirely
composed of rock that is relatively young.
D. New rock is formed only along boundaries where two plates are moving toward one another
and all of these types of boundaries are within ocean basins.
Item ID: PT-RE53
Key: D
P-value: 0.49
Percent Responding:
A
B
C
D
19%
19%
14%
49%
Primary Sub-Idea(s) Assessed:
J: Old ocean floor rocks return by subduction into Earth’s interior. Hence, ocean floor rocks are relatively
young. Most continental rocks stay at Earth’s surface because of their low density (although sediment eroded
from the continents is carried to the oceans and can be subducted along with oceanic lithosphere). Hence, the
age of some continental rock is quite old.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
Students in a science class are studying plate tectonics. They look at a series of diagrams showing
the breakup of Pangaea. One student asks,
“Is the material that makes up the continents today the same material that
made up Pangaea?”
Of the following, which one would be the best response to the student’s question?
A. “No. While the continents may look like they came from Pangaea, all rock is continually being
recycled through the mantle and added back to Earth’s surface.”
B. “Yes. Most of the land of Pangaea still exists today because plates move so slowly that they
have little effect on each other.”
C. “Yes. The present-day continents broke off from Pangaea and floated across the oceans into
their current positions.”
D. “Yes. The continents that broke off from Pangaea remained at Earth’s surface because they are
less dense than the rock that makes up the ocean floor.”
Item ID: PT-RE54
Key: A
P-value: 0.44
Percent Responding:
A
B
C
D
44%
5%
9%
42%
Primary Sub-Idea(s) Assessed:
J: Old ocean floor rocks return by subduction into Earth’s interior. Hence, ocean floor rocks are relatively
young. Most continental rocks stay at Earth’s surface because of their low density (although sediment eroded
from the continents is carried to the oceans and can be subducted along with oceanic lithosphere). Hence, the
age of some continental rock is quite old.
Content Level: 2 – Using science content knowledge to analyze/diagnose student thinking
After studying the recycling of Earth’s plates, a student asks,
“How can we have some rocks that are nearly as old as Earth itself if Earth’s
plates are always being recycled?”
Which one of the following is the best answer to the student’s question?
A. The rock that makes up Earth’s continents is rarely subducted and has stayed on, or near,
Earth’s surface.
B. The spreading centers along some plate boundaries have been actively producing rock for a
very long time.
C. Even though Earth’s plates are recycled, the rock that makes up the plates stays unchanged and
is thus nearly as old as Earth.
D. Earth’s plates move so slowly that many of them have not had time to reach a subduction zone
and be recycled.