Burette Races - Cover Sheet SCI Home | SCI Faculty Page | Case Notes | Reference List | Users Notes

Author - Caleb Arrington/John Shepherd - Summer 1998
This exercise was done by Caleb in Spring 1998, written by John in Summer 1998 and tried out in the May 1998 Faculty workshop.

Case Purpose This case introduces basic observation and description in an experimental situation. The students must organize their observations into a general patten that will allow them to make a precise prediction. The case can also be used to introduce the power of quantification as a tool in description and math (graph symbology and perhaps equations) as a tool for symbolic manipulation and inference.

Relation to Texts This experiment gives practice with basic experimental method, careful observation, and careful laboratory work. The first part of the exercise is phenomenology; they are asked to describe what happens in a careful way (Ziman, RK, 2.5)

This case works well as part of Giere Chapter 2, reinforcing the relationship between "Real World," "Model," "Prediction," and "Data."

Description of Case Materials This case requires a set of burettes, stands, beakers and stopwatches, with one set per group. These may be borrowed from the Biology or Chemistry Departments. Each group will also need some graph paper or access to a computer to record (and display) their data. A set of instructions for the students is available also (Word 97, Word 95).  A set of directions that fit better with Giere is available also.

Case Use Student groups are shown the apparatus and how to use it to measure volumes. They are asked to describe the phenomenon of water release by drawing a graph of burette volume as a function of time since the stopcock is opened. They are told they will have to use this graph to make an accurate prediction about the time required for any given volume from any given starting point. They are given limited time to collect data and to construct their graph and are told their group grade depends on the accuracy of their prediction. As a competitive bonus, the most accurate group will get bonus points. This part of the work should be done in a single period. After each group's prediction is tested, a more general discussion can raise the difference between empirical models and laws and explanatory theory.

Reference List none