What are some ways that the Water in a Hose analogy doesn work?
• It gives the erroneous idea that electrons are substance-like, rather than process-like. • The hose is empty before the water enters it. This could inadvertently reinforce a Cyclic Sequential Model instead of a Cyclic Simultaneous Model. • It does a nice job conveying that less water gets through, but doesn’t convey the aspects of resistance that are related to difficulty of electron movement. • In order to think about the result of resistance on current, one has to think about what comes out of the hose, but a circuit does not have a similar “ending.” This could inadvertently reinforce a Linear Model. • In reality, one clamp on a water hose would decrease the flow of water. However, it is not clear whether a second clamp would actually affect the system in the same way that a second light bulb adds additional resistance in a circuit. So increasing the number of clamps is not directly analogous to adding bulbs and therefore increasing resistance. What questions do students have? What
