How does a touch sensor work?
Inside the touch sensor is an electric switch that is connected to the touch sensor plunger. When released, the switch is open and when depressed the switch is closed. The RCX can sense the voltage difference between the two states. A current limiting resistor is added in series to the circuit to prevent damage to the RCX in the case the switch get connected to a motor port. Here the individual was probably interested in how to use the switch in a program or perhaps how to use it in a mechanism. What they got was an accurate answer to the question asked, but not the information they wanted.
