Creating Physicists: Making reasoning explicit: metacognition and the relative value of evidence

Lawson Primarily a hypothetico-deductive process Make an observation of a “strange” phenomenon, generates tentative theories, deduce specific predictions to test these theories through experimentation. Requires skills: properly identify and control variables, proportional, probabilistic, and correlation thinking. Allchin and others Inductive processes a major component Induction a useful tool for identifying regularities, patterns, and associations “proper” science reasoning can be done even when limited theory or prior concepts exist to guide initial observations.

Conservation Proportional Isolation and control of variables Probabilistic Correctional (correlation vs. causation) Hypothetico-deductive

Epistemological Beliefs of Students Students rely on more rote learning strategies when they hold a positivist view of science: science as an existing body of knowledge to be discovered by authority and/or passive observation Edmondson, K.M. & Novack, J.D., Journal of Research in Science Teaching 30, (1993) Students holding a constructivist epistemology typically are far better at making connections and constructing experiments; they also demonstrate greater ability to achieve significant gains in conceptual knowledge. Edmondson, K.M. & Novack, J.D., Journal of Research in Science Teaching 30, (1993). Tsai, C.-C., Science Education 82, (1998). Moore, J.C., European Journal of Physics Education, 3(4), 1-12 (2012).

Personal Epistemologies “in the moment” Demonstrating the ability to switch between epistemological resources in approaching a problem is an indicator of what is called the “journeyman-expert transition” Bing, T.J. & Redish, E.F., Physical Review STPER 8, (2012). “Expertness” not defined by how good someone is at getting the “correct” answer. How good are they at deploying multiple resources in their strategy in the moment.

Metacognition and Epistemological Resources The “expert” consistently evaluates their own thinking and utilizes multiple resources towards solving the problem. The “novice” is typically “stuck” in one frameing and rarely evaluates their own reasoning.

Probability of Dynamic Visualization LCTSR Score Epistemic Threshold Moore & Slisko, Proc. GIREP (in press). “Seeing” multiple resources

Metacognition: A Framework 1.How do students approach a particular task? 2.Bin their responses. 3.Class discussion on the various approaches. 4.Use multiple groups investigating the same phenomena. 5.Class “conferences” (usually have “weird” outliers). 6.Class discussion on the relative value of evidence.

IF … AND … THEN … hypothesis test result if hypothesis is true

Is current used up in a bulb? S1: If we add another bulb to the circuit, and we observe the brightness to decrease, then current is used up in bulbs. S2: If Ohm’s Law is valid, and the current decreases when the voltage decreases, then current is used up in bulbs. S3:If we conduct a controlled experiment varying only the current, and the bulbs behavior does not depend on the current, then current is not used up in bulbs.

Where does group guided-inquiry fail? S1: If we add another bulb to the circuit, and we observe the brightness to decrease, then current is used up in bulbs. S2: If Ohm’s Law is valid, and the current decreases when the voltage decreases, then current is used up in bulbs. S3:If we conduct a controlled experiment varying only the current, and the bulbs behavior does not depend on the current, then current is not used up in bulbs.

What Students Do 1.The student devises a testing experiment that does not test the hypothesis/model under review. The actual experiment may be valid in a different context, but does not test within the immediate context. This approach is exhibited by S1 and partially by S3. 2.The student appeals to the authority of a specific rule/law/model, person, or previous passive observation. This approach is exhibited by S2. 3.The student recites previously learned jargon concerning the “scientific method,” such as independent and dependent variables, controlled experiments, etc. without explanation or definition within the immediate context. This approach is partially exhibited by S3.

“If current is used up in bulbs, and we conduct a controlled experiment varying only the independent variable, then the behavior of the bulb will not depend on the independent variable.” Let’s Discuss

“If current is used up in bulbs, and we add another bulb to the circuits, then the bulb will get dimmer.” Support vs. Proof Half of the groups are instructed to add a bulb in series. Half are instructed to add a bulb in parallel.

“If current is used up in bulbs, and we add another bulb to the circuits, then the bulb will get dimmer.” Support vs. Proof Relative value of evidence

Metacognition: A Framework 1.How do students approach a particular task? 2.Bin their responses. 3.Class discussion on the various approaches. 4.Use multiple groups investigating the same phenomena. 5.Class “conferences” (usually have “weird” outliers). 6.Class discussion on the relative value of evidence.

“A single bulb circuit consists of a battery, two wires and a bulb arranged such that the bulb is lit. A student wonders whether it matters which part of the bulb is connected to the ‘+’ sign on the battery. Describe an experiment that the student can do to make this determination.” Grounded Theory: How do “novices” approach testing experiments? Moore, J.C., European Journal of Physics Education, 3(4), 1-12 (2012).

S1: The orientation of the battery does not matter, so rebuild the circuit in exactly the same way to show that the orientation does not matter. S2:Get a different battery, bulb and set of wires and build a second circuit with the battery in the opposite orientation. S3:Using the same components, turn the battery in the opposite orientation. S4:Conduct a controlled experiment, varying only the number of batteries to see if that makes a difference. S5:Redo the experiment, but make sure it is controlled by holding all independent variables constant; then measure the bulb brightness Moore, J.C., European Journal of Physics Education, 3(4), 1-12 (2012).

S1: The orientation of the battery does not matter, so rebuild the circuit in exactly the same way to show that the orientation does not matter. S2:Get a different battery, bulb and set of wires and build a second circuit with the battery in the opposite orientation. S3:Using the same components, turn the battery in the opposite orientation. S4:Conduct a controlled experiment, varying only the number of batteries to see if that makes a difference. S5:Redo the experiment, but make sure it is controlled by holding all independent variables constant; then measure the bulb brightness Moore, J.C., European Journal of Physics Education, 3(4), 1-12 (2012).

S1: The orientation of the battery does not matter, so rebuild the circuit in exactly the same way to show that the orientation does not matter. S2:Get a different battery, bulb and set of wires and build a second circuit with the battery in the opposite orientation. S3:Using the same components, turn the battery in the opposite orientation. S4:Conduct a controlled experiment, varying only the number of batteries to see if that makes a difference. S5:Redo the experiment, but make sure it is controlled by holding all independent variables constant; then measure the bulb brightness Moore, J.C., European Journal of Physics Education, 3(4), 1-12 (2012).

S1: The orientation of the battery does not matter, so rebuild the circuit in exactly the same way to show that the orientation does not matter. S2:Get a different battery, bulb and set of wires and build a second circuit with the battery in the opposite orientation. S3:Using the same components, turn the battery in the opposite orientation. S4:Conduct a controlled experiment, varying only the number of batteries to see if that makes a difference. S5:Redo the experiment, but make sure it is controlled by holding all independent variables constant; then measure the bulb brightness Moore, J.C., European Journal of Physics Education, 3(4), 1-12 (2012).

S1: The orientation of the battery does not matter, so rebuild the circuit in exactly the same way to show that the orientation does not matter. S2:Get a different battery, bulb and set of wires and build a second circuit with the battery in the opposite orientation. S3:Using the same components, turn the battery in the opposite orientation. S4:Conduct a controlled experiment, varying only the number of batteries to see if that makes a difference. S5:Redo the experiment, but make sure it is controlled by holding all independent variables constant; then measure the bulb brightness ??? ? Moore, J.C., European Journal of Physics Education, 3(4), 1-12 (2012).

S1: The orientation of the battery does not matter, so rebuild the circuit in exactly the same way to show that the orientation does not matter. S2:Get a different battery, bulb and set of wires and build a second circuit with the battery in the opposite orientation. S3:Using the same components, turn the battery in the opposite orientation. S4:Conduct a controlled experiment, varying only the number of batteries to see if that makes a difference. S5:Redo the experiment, but make sure it is controlled by holding all independent variables constant; then measure the bulb brightness Moore, J.C., European Journal of Physics Education, 3(4), 1-12 (2012).

S1: The orientation of the battery does not matter, so rebuild the circuit in exactly the same way to show that the orientation does not matter. S2:Get a different battery, bulb and set of wires and build a second circuit with the battery in the opposite orientation. S3:Using the same components, turn the battery in the opposite orientation. S4:Conduct a controlled experiment, varying only the number of batteries to see if that makes a difference. S5:Redo the experiment, but make sure it is controlled by holding all independent variables constant; then measure the bulb brightness Moore, J.C., European Journal of Physics Education, 3(4), 1-12 (2012). Here, we give half of the groups nearly dead batteries.

A Success Story X O Sikkema et al., Am. J. Phys., 78, 467 (2010).

“If the tube bobbles, and we ink one side, then a circle will be traced out on the page no mater what side is initially pressed.” x x o o x x o o or

Thursday, April 7 th … Making reasoning explicit: the relative value of evidence Getting students to think about how useful their data really is.