d body language. Software is used to monitor the various input devices and to determine whether the individual is too busy to bother with an incoming voice call or text message. "The idea is to get the telephone to act more as an assistant than a tool," says Fogarty, a Carnegie Mellon doctoral student. Under one approach, the sensing infrastructure would be independent of the communications device but able to communicate with the unit. "You could instrument an office, for example," notes Fogarty. Homes, cars, and other loca- tions could also be equipped with sensors to monitor their inhabitants' activ- E-MAIL LEADS TO INSTANT MESSAGING ities. An alternative approach would be to build the infrastructure, perhaps including a camera, microphone, and movement-detecting accelerometer, into the communications device itself. "That would probably be the least expen- sive approach," says Fogarty. The researchers recently tested their technology, using 24 sensors, on four individuals engaged in work activities. The subjects were asked at random intervals, on a five-level scale ranging from "highly interruptible" to "highly not-interruptible"-how willing they were to be bothered with a phone call. The researchers then correlated the subjects' preferences with their behaviors. Not surprisingly, the test showed that the subjects were least likely to appre- ciate an interruption while typing on a keyboard, talking on a phone, or speak- ing with someone else in the office. What did surprise Fogarty and Hudson, however, was the fact that the computer was slightly more accurate than human observers at predicting when an individual was willing to be inter- rupted. The computer successfully predicted the subject's preference 82 percent of time while humans managed only 77 percent accuracy. Hudson believes that the test results will carry over successfully to the real world, particularly in business settings. "I'm confident that the results will apply to communications-oriented people such as managers," says Hudson a professor at th