Designing Demos to Promote Inquiry – The Two Eggs Dilemma

The more that I reflect upon my practices in light of student-centered inquiry, the more I realize points that need refinement.  Demonstrations are one of these areas, so I thought I’d share how I have reworked a very good demo into a student-centered inquiry experience.

The demo is a classic for the illustration of inertia; simply take two eggs and boil one of them.  Spin them for several seconds on a lab table, then stop both momentarily.  As soon as you release them, one of the eggs will begin to slowly rotate again.  This experience, in and of itself is a good exercise to emphasize qualitative observations in light of student understanding of Newton’s First Law.  It is also tempting to show students the demonstration and then explain what just happened.  But good inquiry never ends up being quick and efficient (just like true processes of inquiry in science research!).

So here is the flow that I utilize with this demonstration:

(1) I explain that I have two eggs, one of which is cooked through.

(2) Students need to explain how to differentiate between the two, without any direct contact with the eggs, only visual observations.  (Students do this orally as well as written on a Google Form)

(3)Spin both eggs; stop and observe.  Students record their observations on a Google Form (see below).

(4) Students advocate for the egg they believe to be raw, citing qualitative data.

(5) I crack open both eggs into a beaker.

(6) Reflection on criteria to identify the raw egg and connect to Newton’s 1st Law.

The demo ends up taking around 30 minutes from start to finish, but it is one that they remember throughout the entire course.

Here is the Google Form that I use for student hypothesis/observation/reflection:



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