If some technology meets the other criteria as described below, it will be made widely available, despite the cost. Good technology is always on . Or if not always on, can be turned on with a single one-stroke command, or better yet, start automatically when the need arises. One thing which makes the telephone useful is that we do not need to boot up the operating system before we make a call. Electrical lights are a significant improvement over systems which required individual ignition with a match or candle.
Streetlights are practical because they turn on when it gets dark outside.
Much of today's educational technology requires long and sometimes cumbersome initialization procedures. After wheeling in the projector from the other room, for example, the three teachers and technician would spend some time plugging it in, turning it on, spooling the film, and positioning the screen. This requirement has significant energy consuption considerations. A portable device, for example, cannot always be on because it must carry its own power supply. Good technology is always connected .