Students made predictions that indicated a range of initial thinking about evaporation. Sample A anthropomorphizes the physical environment by saying that “the rain forgets the salt and leaves it behind.” Samples D, E, and F all predict that something will happen to the salt in the evaporation process. Sample D thinks the salt in the water will evaporate, with the picture indicating some of the salt in the side of the clouds. Sample E sees the water and salt separating as it evaporates up into the clouds. Sample F predicts an entirely separate process during evaporation in which the “air filters out the salt.” Sample B and C are the only student samples in which thinking indicates the salt will remain in the ocean during evaporation.

After the demonstration, Samples D-F all noticed that the salt did not evaporate, but remained behind in chunks of salt in the tin. No evidence is shown of student thinking for what they now think about the mechanism of evaporating salt water.