Transcript What We Learned by Moving Beyond Content

WHAT WE LEARNED BY MOVING BEYOND
CONTENT UNDERSTANDING AND
DIVERSIFYING OUR RESEARCH AGENDA
Mel S. Sabella
Chicago State University
Department of Chemistry and Physics
PERC 2010
Supported by the NSF Course, Curriculum, and Laboratory Improvement
Program and the NSF Robert Noyce Teacher Scholarship Program (0632563,
0618128, 410068, 0833251)
Thinking like a physicist …



scientific thinking (i.e., reasoning skills and
argumentation practices that feature significantly in
physics);
critical thinking (i.e., general logical reasoning as
applied to, or necessary for, doing physics); and
reflective thinking (i.e., thinking about one's own thinking
and learning processes)
Sometimes our students do this
and sometime they don’t …
Observations …
Our students
 are capable of thinking like a physicist
 engage in thinking like a physicist in certain situations
We’re interested in figuring out when students think like
a physicist and when they don’t - activation
focus: reflecting on the activation of formal physics
knowledge and helping students reconcile intuitive and
formal physics knowledge
focus: reflecting on the activation of formal physics
knowledge and helping students reconcile intuitive
and formal physics knowledge
Why is this important?
Initially a lot of our assessment focused on the
individual’s content understanding and how the
individual was changing as a result of the course.
These focused on performance on exams and
diagnostics …
What happens when our focus is narrow?
Beyond the concepts …
F06 (C)
F06
S09
S07
S06
F05
S05
F04
F09
S00-S04 (C) (ave)
F05, S07
F01(A)
- (average)
Going to start with some old data …
Results from diagnostics at F08
Chicago State U:
F07
Force Concept Inventory
S08
Fit to distributions for 35 classes
at 7 universities, UMD PERG
A lot of things go through your head …
Not too good?
Bad day?
Smart kids were absent on the posttest?
Wait till next semester!
But in class things seem really good?
How can we tweak the activities even more?
Interpreting this data …
The students do not understand these concepts and have not
developed a correct, robust understanding of these ideas …
another way to interpret the data: students are not thinking
like a physicist.
students are not engaged in reasoning and reflective
thinking …
its really not about newton’s 2nd law
Some old data
But its data I really like …
And it’s got drama, action, and humor …
Understanding student
models of learning
The force sled questions
Example: from FMCE (Thornton and Sokoloff)
A sled moves on ice. Friction can be ignored.
Students are asked a series of questions about
the type of force that would cause the sled to
move a particular way.


 F  ma
Students typically do poorly on these questions.
Conducted one-on-one interviews
Sabella and Cochran, 2003 Physics Education Research Conference Proceedings (2004)
What force would keep the sled moving to the right at
a constant velocity?
Initially the student says that you would need to
provide a constant force to the right.
Interviewer asks student to explain.
An excerpt from later in the interview …
Intuitive ↔ Formal
Newton’s
13 Laws
Motion
decreases
Interviewer :
“… you’re
saying [it] would
stop eventually?”
Interviewer further
probes: “You said it
would continue to
move, but the motion
would decrease?”
Because you’ve removed the … push that caused it to move in
the first place … Newton’s law. It’s either the first or the
second …
Okay. … Newton’s law says that an object that’s in motion will
remain in motion. So, it’s going to remain in motion and
that’s why it wouldn’t stop right away.
Yes, I did say that. Oh. Okay. I have to change that answer.
Newton’s law is saying that an object in motion stays in
motion … So, if you’re pushing the sled you’re causing it to
move and you let go, let go, and you stop pushing it then the
sled would continue to move …
but the motion would just decrease. The motion would
decrease in velocity.
No, let me change that answer … Okay, this is my final answer.
If you’re applying a force … and you stop pushing it,
Newton’s first law says that an object in motion stays in
motion so it’s just going to keep on moving.
Intuitive knowledge
When students are presented with these problems
 students
tend to give a quick response.
 there is little reasoning involved.
Intuitive
knowledge
Force-Sled
question
Formal
knowledge
14
Another example:
negative
means slowing
down
Interview excerpt:
[student explains the relationship between velocity and
acceleration when an object is slowing down/speeding up]
a, v same
sign 
speeding
up
… when … speeding up, the velocity and acceleration have to be
the same … positive and positive - that means speeding up - or …
negative and negative –
- which means slowing down –
- well not - when they’re the same it’s kinda like speeding up when they are opposite it is slowing down.
So, if it is a minus and a minus
… it’s slowing down –
- no - I'm saying it wrong …I'll say it this way …
So…


Students seem to have the content knowledge
But it takes us looking beyond the content
knowledge to find it
(In this example we needed to look at the thinking and
reasoning skills of the students)
Takes support …
In this example we saw that the activation of the
formal knowledge happened in the context of a
scaffolded environment (the interviewer –
interviewee)
something we see often – the community environment
can place the students in a mode in which formal
knowledge is more easily activated
– a mode in which they are thinking like a physicist
Clicker questions are one tool to allow us to look
at the both community knowledge and individual
knowledge in the context of the community.
sample clicker question sequence
An object starts 1m to the
left of the origin and
travels to the right with a
constant speed of 3m/s.
Use a coordinate system in
which the positive direction
is to the right. Choose the
equation that describes the
position of the object as a
function of time.
+
1) x  3 m s t + 1m
2) x  -3 m s t + 1m
3) x  1mt + 3 m s
4) x  -1mt + 3 m s
5) x  -3 m s t - 1m
6) x  3 m s t - 1m
7) x  -1mt - 3 m s
8) x  +1mt - 3 m s
the study
Erica P. Watkins
An object starts 1m to the left of
the origin and travels to the right
with a constant speed of 3m/s.
Use a coordinate system in which
the positive direction is to the
right. Choose the equation that
describes the position of the
object as a function of time.
+
1) x  3
2)
3)
4)
5)
6)
7)
8)
t + 1m
x  - 3 m s t + 1m
x  1 mt + 3 m s
x  - 1 mt + 3 m s
x  - 3 m s t - 1m
x  3 m s t - 1m
x  - 1 mt - 3 m s
x  + 1 mt - 3 m s
m
Students used the clickers to answer
the question in lecture.
Students first answered on their own
and then were able to discuss the
question amongst each other and
re-vote.
s
The same question was asked on the
test.
The only difference was that on the
test there was an option for “none
of the above”.
the study
An object starts 1m to the left of
the origin and travels to the right
with a constant speed of 3m/s.
Use a coordinate system in which
the positive direction is to the
right. Choose the equation that
describes the position of the
object as a function of time.
Lecture 1st Try
(individual)
3 m/s t + 1 m
-3 m/s t + 1 m
+
1) x  3
2)
3)
4)
5)
6)
7)
8)
t + 1m
x  - 3 m s t + 1m
x  1 mt + 3 m s
x  - 1 mt + 3 m s
x  - 3 m s t - 1m
x  3 m s t - 1m
x  - 1 mt - 3 m s
x  + 1 mt - 3 m s
m
s
Students
1 m t + 3 m/s
-1 m t + 3 m/s
-3 m/s t – 1 m
5 of 16 correct
Correct
3 m/s t – 1 m
Does not include students who did not
complete clicker questions
response progression
Lecture
1st
Try
Lecture 2nd Try
Test
(individual)
(working
together)
3 m/s t + 1 m
3 m/s t + 1 m
3 m/s t + 1 m
-3 m/s t + 1 m
-3 m/s t + 1 m
-3 m/s t + 1 m
1 m t + 3 m/s
1 m t + 3 m/s
1 m t + 3 m/s
-1 m t + 3 m/s
-1 m t + 3 m/s
-1 m t + 3 m/s
-3 m/s t – 1 m
-3 m/s t – 1 m
-3 m/s t – 1 m
Correct
Correct
Correct
3 m/s t – 1 m
3 m/s t – 1 m
3 m/s t – 1 m
Other
the study
Does not include students who did not
complete clicker questions

A

B
ClickerQ 1
A+ B 
Choices
Q3
Exam Question
ClickerQ 2 Clicker
 
 
A - B  2 A - B  2B - A 
 
A+ B 
 
A- B 
 
2A - B 
 
2B - A 
Clicker Q1
Clicker Q2
Clicker Q3
Exam Q
A
A
A
A
B
B
B
B
C
C
C
C
D
D
D
D
E
E
E
E
69% correct
N=16
81% correct
N=16
94% correct
N=16
42% correct
N=12
 
2B - A 
Exam Q
The most common response was a
response consistent with the
vector A + B

A

B
One possible explanation for this is that
on an exam, students engage in a
different response mode.
A
B
C
D
E
42% correct
N=12
The community and the individual

Community




Argumentation practices
Reflection on group statements
Shared responsibility for learning
Individual ideas in the context of the community
It’s what happens in the classroom
- something we do well

Individual



The environment can
trigger which of
these modes the
students go into.
Reasoning skills
Reflective thinking
Differentiating between intuitive knowledge and formal knowledge
It’s what happens at home, on tests, on diagnostics …
- something we struggle with
what the csu classroom looks like “Central to productive learning environments are
individuals who act not only for themselves, but also
for the collective … they enact practices not only
intended to promote their own achievement but also
to expand the agency and learning of others”
Ken Tobin (Sociocultural Perspectives on Science Education)
part of thinking like a physicist …
part of what we do well
One of the reasons it looks this way
“… more traditional science classrooms tend to
favor those students who are already academically
successful …”
Paul Vellom and Charles Anderson, Reasoning about data in
Middle School Science, Journal of Research in Science
Teaching, 36 2 179-199 (1999)
The danger in relying on community …
Students engage in different reasoning modes in the
community environment and the individual environment.
How do we move the community mode of reasoning
(and thinking like a physicist) to the individual?
Shifting back the individual …
Do students recognize that they have these diverse
knowledge sets that can contradict each other?
and
Do they recognize the difference in these
modes of reasoning?
A new type of pretest
Pretests serve two roles:
1) they are an instructional tool
2) they are a research tool
Use the pretest to help bridge the intuitive and formal
knowledge connection
Without Thinking Too Hard! What does your intuition
tell you about …
How would you answer using the ideas from the
physics class? …
Example from buoyancy
Two cubical blocks of equal volume are placed
in water. Block A is found to rest at the bottom
of the tank while block B is found to float as
shown.
Without Thinking Too Hard! What does your
intuition tell you about whether the buoyant
force on block A is greater than, less than, or
equal to the buoyant force on block B?
Explain.
How would you answer using the ideas from the physics class? Is the buoyant
force on block A is greater than, less than, or equal to the buoyant force on block
B? Explain.
Before covering the topic, most students state that B has a greater buoyant force
because it is floating. (8 of 14, S09)
A>B
Results
Without Thinking Too
Hard! What does your
intuition tell you about…
Intuitive (quick)
Response
Greater than
Less than
How would you answer
using the ideas from the
physics class?
Formal Knowledge
Greater than
75 % (9)
17 % (2)
N=12 (students who
omitted one part not
included.
Less than
0%
8 % (1)
Intuitive (quick)
Response
Formal Knowledge
Greater than
Greater than
Less than
because it sank to the bottom
displaces more water
displaces more water
it sank to the bottom
the more surface that touches the water
the more buoyant force
because A sank to the bottom
displaces more water
block A is heavier so displaces more
Less than
75 % (9)
17 % (2)
Intuitive (quick) Response
displaces more water
N=12 (students who
omitted one part not
included.
0%
8 % (1)
Formal Response
more weight and fluid being displaced
displaces more water
displaces more water
more displacement, that's why it sank
has more of its surface under the water
more weight making it sink - would displace
the water
A is being pushed by the water all the way
buoyancy is the displacement of liquid by
object
displaces more water
Intuitive (quick)
Response
Greater than
Less than
Intuitive (quick) Response
No Reason
because B is floating
Formal Knowledge
Greater than
75 % (9)
N=12 (students who
omitted one part not
included.
Less than
0%
17 % (2)
8 % (1)
Formal Response
Displaces more water
Displaces more water
In a class of 18, these two students received the highest scores in the
class.
NOVA’s comments on the pretests
These pretests involve how you would answer intuitively and
formally. Would your responses be different on these two questions.
Nova:
If I, if it’s a pretest and I really didn’t know, they
probably would be different. But since I was already taught it,
my gut reaction would probably be my physics reaction.
…
Nova:
If I already knew, the first one [it] probably would
not be as detailed as the second one.
…
Nova:
But [it] would probably be around the same answer
Reflective practices to identify connections
between intuitive and formal knowledge …
conducted a series of one on one interviews with
students assess these reflective practices
I have a specific idea about what I mean by formal
physics knowledge: it’s the definitions, laws, rules,
concepts that allow me to address specific tasks.
When students say they are using their formal physics
knowledge – what do they mean …
The line between the intuitive ideas and the physics
ideas maybe blurred …
Interview excerpt …
GABBY





GABBY: ummm…an elevator is being lifted up at constant speed … So, the
upward force has to be greater than the downward force of gravity …
I: And is that something from physics 1 or is that just common sense?
GABBY: Ummm…physics 1
I: Do you remember specifically what you’re using…
GABBY: Well I remember you taught us about ummm…if something moves
there has to be a force. So of course there is a force on gravity and I
guess like the tension from the wire. So if the frictional force is negligible
there is no other force … if it is going up something has to push it up that is
even greater than gravity because in order for it to move the net force
would have to go up … Uh huh, like ummm…what were they called…the
body diagrams … Free body diagrams, yes.
Interview excerpt …
GABBY


I: … so do you remember the specific idea from physics 1 that…
GABBY: I remember a lot of stuff, but I’m not exactly sure what you’re….
…, so like I know you told us …about a lot of things I mean you taught us
about forces, velocity, acceleration … quite a few things you know … I just
don’t know exactly what you’re referring to … I know that because it’s
moving that means that I increase, well it means that it is obviously
accelerating. It accelerated because it was still, so I know that it is going
somewhere it’s like the cars. How do I explain this …So I know something is
happening, I’m not sure exactly what like you’re referring to. Like I know
that it is this because obviously I’m moving it. But I guess you’re trying to say
like what topic? … Like sum of the forces equals mass times acceleration
or…
At this point GABBY brings up NII, notices that it is constant velocity so zero acceleration and gives
the correct answer.
Interview excerpt …
GABBY – cont.
Interviewer asks her to explain the chain of reasoning… (she just used the NII argument)

…How do I know that? …forgot that thing that you told us. I know how to
explain it, I do, but it’s not coming to me …well I guess I can say that the
reason I know it’s the same magnitude because the forces have to be equal
if it’s moving at a constant speed because if it was greater then I guess it
would change - it wouldn’t be at a constant speed. So if it’s not then
obviously one of the forces would have to be greater …the reason I know
it’s the same magnitude is for that reason, but they have to be equal if it’s
going to stay at the same. Like it’s constant speed to me is like it is the same
as sitting still …
Answering on autopilot …
Interview excerpt …
GABBY
Answers with #5 then later in the interview draws a FBD …
GABBY: I originally picked #5 … I think I was just...its going this
way and this is going this way ... I was just moving through it …
I: Why come you didn't draw a diagram at first?
GABBY: Intuition thing - I think I should be working on more physics
than on the intuition...I mean I think it helps but it should be
physics...and in any case sometimes in physics you have to write it
down...you have to draw yourself a picture...and think about it … I
think sometimes … intuition and physics go really close like when I
think of intuition I think of what I see in real life …
These are small projects …
We are still working on understanding:
 the difference in reasoning modes from the community
environment to the individual environment
 how we can help students
connect their intuitive knowledge and their formal
knowledge
 understand what we mean by intuitive and formal
knowledge

think like physicists
Community to the individual

Continue
 to
use class consensus building
 to emphasize the idea of collective knowledge
 to emphasize the shared responsibility of the community

Make explicit
 How
you succeed without the community resource
 Strategies for reflective thinking in all enviroments
Intuitive to the formal
Help students:
 See
the value in both these types of knowledge (don’t
abandon the intuitive knowledge)
 Activity seek consistency between these two types of
knowledge.
 Understand what we mean by formal knowledge and
explicitly describe how the formal physics knowledge
helps you address different tasks.
What am I suppose to be doing when you ask me
these questions?