Preliminary open-ended PCK-Q question

SAMPLE PCK-Q QUESTIONS

PCK-CM-1

Context: Students have learned about free body diagrams and Newton’s 2nd law. A group of students is working on a question about a block sliding down a frictionless inclined plane. They are required to draw a force diagram to explain why the block slides down. You approach that group, notice their force diagram as shown below, and have a conversation with one of them PCK-EM-1

Context: Context: Students have learned parallel and series circuits, Ohm’s law, and power. They are exploring brightness of light bulbs in different cases. Students are presented with a picture of three setups a) a single bulb in a circuit with one battery; b) two bulbs in series in a circuit with one battery; and c) two bulbs in parallel in a circuit with one battery. All the bulbs and batteries are identical. They are ranking the brightness of the bulbs. LA-2 a. What can you conclude from the information provided about the student’s physics content knowledge, both the strengths (i.e., what he/she knows) and difficulties (i.e., what he/she does not know)? Answer with “n/a” if you think there are no strengths OR difficulties in students’ understanding. Strengths: The student understood that there is a relationship between the brightness of the lightbulb and the power of each lightbulb. The student understood the power at each lightbulb and how the different circuits affect them. The student answered the question correctly with the correct reasoning. Difficulties: n/a b. How would you respond to the students? Please use direct quote of what you would say. What is(are) your purpose(s) behind that response? “Ok, what if you had a drawing like this? What would you rank the brightness of these light bulbs?” Since the students answered correctly and understood the problem, I would propose another question or make the current question more complicated, by changing the third picture (c) to have another light bulb in series in the parallel circuit. 