WATER TASTE TESTS SUPPLEMENT THEORY IN GEOLOGY LABORATORY EXERCISES

Many students enroll in introductory geoscience courses because they perceive geology to be a relatively painless, qualitative remedy for science requirements. However, it is essential that educators introduce all students to the quantitative tools that form integral components of modern scientific endeavors. Recognizing that students express enthusiasm for "hands-on" activities, we have begun to modify our approach to teaching quantitative methods in the introductory earth systems science laboratory. To engage more students and to enhance their educational experience, we have incorporated an experiential activity - water taste testing - into a previously all-quantitative global water balance exercise.

The water tasting is conducted as a blind taste test during the first hour of a three-hour lab period. Bottled drinking waters are chosen to represent different geological settings, and tap water is disguised as a commercial bottled water. After students taste the waters and rate them on a scale of 1 to 5, we tally the scores and reveal the waters' identities. The post-test discussion leads to comparisons of the geology of the waters' source areas, and questions about the waters' compositions. The tap water samples usually rank favorably in comparison with some of the name-brand bottled waters, leading to calculations of the cost of a gallon of bottled water and a consideration of economic factors. Students spend the final two hours of the lab period using the computer program STELLA to construct a global water balance model into which they incorporate different scenarios of population growth and water consumption.

Last year the introductory earth systems science students generally rated the STELLA-only water cycle exercise unfavorably. After adding the water tasting this year, students rated the lab substantially more favorably. To dilute some concerns about the apparent simplicity of the exercise, next year we plan to strengthen the connection between observation and computation through more directed questions about water balance issues. The positive feedback we received indicates that by combining a sensory experience with a quantitative exercise, we can provide students with an immediate practical application as well as food for thought in their roles as scientifically literate citizens.