Subject: Stocks and Flows

Posted by John Gunkler on 3/9/2004
In Reply To:Stocks and Flows Posted by Lees Stuntz on 3/2/2004

Message:

From a pedagogical perspective, maybe we should approach the subject of stocks and flows a little more like a discovery problem. That is, maybe we should simply offer examples of stocks (the water in a bathtub, pollutants in a stream or lake or the atmosphere, cash in a bank account, resentment in a fictional character, good will toward you in your parents, the esteem of classmates, the affection of a girl/boyfriend, willingness to do some activity, skill at a sport, etc.) and then ask the students, "What can increase this?" and "What can decrease this?" In other words, let them offer suggestions for flows.

Of course, some of their suggestions may not be flows, some may be flows if you and they can agree on an operational definition, and some may be flows but don't directly affect the stock. These are learning opportunities and offer a chance to use some other SD tools (like CLD's or stock-flow diagrams) to show why the suggestions work or don't work. This way the tools of SD are introduced as tools -- that is, as something that is useful for accomplishing something the students care about, like clarifying why their suggestions work or don't work.

Follow Ups:

Stocks and Flows - Bill Ellis 3/10/2004