The "Drivers' Test" is a simple, multiple choice exam to encourage the students to study the website materials in a serious manner. The test is recommended to make sure the students acquire a fundamental knowledge of the terminology, units of measure and interconnections in the system. They need to master the "pieces" before they begin to think of how the "pieces fit together as a system."

Some students (and even some instructors) skip the drivers' test because they are eager to begin experimenting with the model as soon as possible. You should resist this temptation. Without some preparation, many students fall into the unproductive pattern of "banging away on the keybord" as if the simulated system were a video game. The "video game syndrome" has been observed in a variety of settings. It is one of the potential obstacles to learning from management flight simulators (Graham 1994, Isaacs and Senge 1994, Senge and Sterman 1994).

The questions are relatively straight forward, and students will find the answers to all but two of the questions on the website. By the time they reach the 18th and 19th questions, some students do not adjust to a question that requires some analysis on their own. They may need your help at this point.

The 18th question asks for the maximum release from Canyon Lake during two months of the year if 4 MAF/yr is released during the other ten months of the year. The average annual inflow is 13 MAF/yr from the previous question. For the lake to refill, average annual outflow will also be 13 MAF/yr (the evaporation loss is quite samll). If we let F stand for the flow during the two month period, the algebraic expression for the annual average outflow would be 13 MAF/yr = (2/12)F + (10/12)4 MAF/yr, and F turns out to be 58 MAF/yr.

The 19th question focuses on the same flow. It asks for the value of F if the inflow to Canyon Lake were somewhat higher because of a land fallowing program in the 3rd irrigation area. The 3rd area is 1 million acres of land with a large diversion requirement and a large runoff. The E&T loss, however, is only 2 MAF/yr. If 50% of the land is fallow, the E&T loss is reduced to 1 MAF/yr, and the annual average flow into Canyon Lake would increase to 14 MAF/yr. The new expression for "F" is 14 MAF/yr = (2/12)F + (10/12)4 MAF/yr, so F turns out to be 64 MAF/yr.