Keep the materials in a bag so the students cannot see them. Organize the students into groups of three. Tell them that you are going to show them four objects and that they will have three minutes to discuss what those objects have in common and to record their responses on paper.Withdraw the objects from the bag one at a time, in the following order: the vinyl record, the cassette tape, the compact disc, and the organism. Repeat the question, "What do these objects have in common?
Allow the groups to discuss the question and record their answers for about three minutes. Then, record the responses on the chalkboard; take one new response per group until you exhaust all responses. You can discuss each response in turn or wait until you compile the complete list and then work through the responses individually, asking for comments from the class.
Among the responses I received were the following:
* They have symmetry. (Yes.)
* They have color. (Yes.)
* They have evolved. (Yes, in the sense that they have changed through time; but only the carnation is the product of organic evolution and artificial selection.)
* They are made of matter. (Yes.)
* They are all solid. (Yes.)