Making complex concepts

accessible through hands-

on analogsAn example teaching Radioactive Decay &

DatingLily Lowery Claiborne

Calvin F. Miller

Vanderbilt UniversityDepartment of Earth and Environmental Sciences

Context & MotivationEarth and Environmental Sciences – 101

2 types of concepts

Familiar, Intuitive, Easily Reproduced in Lab

Not Visible, Unfamiliar, Non-intuitive, Cannot be Reproduced in Lab

QuestionsCan 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

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

Study DesignAll Students in Intro Geology (~100)

1. Students attend traditional lecture on topic2. Students come to lab in groups of ~20

- Take pretest on topic- Perform analog activity- Take post-test (identical to pretest)

Student Activity (briefly)

Parent Isotope

Daughter Isotope Decay

Fluid pressure behaves the same way

as Radioactive Decay

Students observe the process of shampoo running through beakers,

observing details & variations

Gather data & plot to create equation

Use equation to date someone else’s 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?”

Conclusions

This Semester

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 activityUnclear questions on pre/post test

•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!