Students will work in pairs to design and build a rain gauge based upon the class research in part 2. Rain data will be collected and analyzed over a period of time with opportunities to improve on rain gauge design. This part of the activity should be conducted during the rainy season in your area.

1. Procedure:
   Have students select a partner (someone they were NOT with during part 1 or 2 of the rain gauge experiments.) Together, they need to design a 'home-made' rain gauge, and justify their design based on the notes they took during the presentation of student data during the mini-meteorology-convention. Design and justification should be submitted prior to students actually building their rain gauge.
2. Each pair of students will create and calibrate one rain gauge, and decide where on the school grounds would be the best location for it. You should obtain permission to put up the rain gauges from your school administration, maintenance, and groundskeepers. Put up a 'real' rain gauge as a control.
3. Have students keep data for several rain events. Provide a way for students to share their data with each other. One possibility would be to create a master spread sheet with student rain gauge names down the side and rain dates across the top. Each student team would record their measurement for each event, and compare it to the control. The spread sheet could calculate such things as the difference between the student gauge and the control; average or median class results; total rainfall over a given time period; etc. Students could quickly see if their rain gauge was not giving accurate results, and decide upon modifications to increase the accuracy.
4. Provide opportunities for students to modify their design, and continue to collect data. Have the class goal be cooperative rather than competetive by stressing something like "we want to reach 100% accuracy for the whole class" instead of "Susan and Tom's gauge is the best so far". This will foster the scientific spirit of cooperation in research that is so necessary for basic science to advance.

Assessment:

• Have students keep a journal describing their experiment, justification for the modifications made over time, individual and class data, newspaper clippings about local storm events, and any other information they find relevant to the experiment.

Extension:

• Have students put up a rain gauge at home, and plot data from all over the community based on student reports from home.