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Making complex concepts accessible through hands-on analogs An example teaching Radioactive Decay & Dating Lily Lowery Claiborne Calvin F. Miller Vanderbilt University Department of Earth and Environmental Sciences Context & Motivation Earth and Environmental Sciences – 101 2 types of concepts Familiar, Intuitive, Easily Reproduced in Lab Not Visible, Unfamiliar, Non-intuitive, Cannot be Reproduced in Lab Questions Can students learn complex, non-intuitive scientific concepts better when they can work hands-on with an analog experiment than through traditional lecture? Can they appropriately transfer the things they learn from the analog experiment to the original concept? Hypothesis YES! Test teaching Radioactive Decay & Dating Study Design All Students in Intro Geology (~100) 1. Students attend traditional lecture on topic 2. Students come to lab in groups of ~20 - Take pretest on topic - Perform analog activity - Take post-test (identical to pretest) Learning Goals • What controls radioactive decay? • How do we use radioactive decay for dating? • Make Predictions about decay/dating • Understand (and use) the decay equation Student Activity (briefly) Fluid pressure behaves the same way as Radioactive Decay Parent Students observe the process of Isotope shampoo running through beakers, observing details & variations Gather data & plot to create equation Daughter Decay Use equation to date someone else’s Isotope experiment Describe what is controlling the process Discuss what this indicates about the process of radioactive decay Results “It slows down as it goes, so as there is less parent, there is less decay.” “The larger the decay constant or the more parent material, the faster it decays!” “If the decay constant depends on what the parent material is, does that mean different kinds of parent isotopes decay at different rates?” “So, if you started running out of parent material, would it decay sporadically, like the shampoo starts to slowly drip at the end?” Student Confidence Quiz Performance pre-test 18 80 post-test Number of Responses 16 70 14 60 12 Number of Correct 50 10 Responses 40 8 6 30 4 20 2 10 0 0 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 relative confidence (lowest to highest) Question Number Conclusions Can students learn complex, non-intuitive scientific concepts better when they can work hands-on with an analog experiment than through traditional lecture? YES – improved understanding and confidence Can they appropriately transfer the things they learn from the analog experiment to the original concept? YES – there was only one student who talked about shampoo instead of isotopes on the post test Problems: Misconceptions Resistance to think past the specific conditions covered in the activity Unclear questions on pre/post test This Semester •Repeat study in all 101 lab sections •Revise questions for clarity •Have students explore variations on the basic system, then ask them to think of others on the post test •Specifically address misconceptions revealed last semester Thank You!
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