In the "old days," children made string telephones out of tin cans and package string -- with perhaps a rusty nail holding things together at each end. These "old fashioned" string phones worked well enough but children now have new materials available to them, undreamed of in earlier times! Using cotton or nylon twine, and paper, plastic, or Styrofoam cups, today's children have plenty of opportunity to improve on the design and performance of the original string telephones, for instance, by making networks and turning corners. But the essence of the string telephone experience has not changed. Children still find that it is just as much fun today to hear a message coming out of an ordinary container, hooked up (by nothing more fancy than a piece of string) to a friend at the other end of the classroom or playground. Though they may have cell phones and beepers in their pockets, children in after school programs still love to play with a simple technology that they can control and build for themselves.
But "play" is only part of this String Telephones project. With the right kind of help, children also have a good chance of understanding how they made their telephones work. This is a design and engineering project -- that calls upon the skills of observation, questioning, explaining and experimentation to improve the performance of the model they are working on. In this project, children experiment with materials (string, cups, nails, tape, etc.) and with the design details (Does the phone work better or worse when the string is tight? straight? touching an object? not touching anything?). It's the children's task to find the best possible combination of all these factors (the optimal arrangement), and to do their best to describe what works and doesn't work with this device.