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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 ClickerQ 1 A+ B Choices Q3 Exam Question ClickerQ 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?