Last year, Jodi Forlizzi’s students rigged a sensor to her office door and linked it to the Web. When her door is open, that information flashes on the site, announcing to students that they are welcome to stop by. When the door is closed — on the Web and in her physical office — students know to leave her alone. “It’s a simple device that came from our study of doors as barriers to interruption,” says Forlizzi, an associate professor of human-computer interaction and design at Carnegie Mellon University.

Forlizzi is fascinated by the questions of how and why busy people get interrupted — and what might be done to minimize distractions. “Wireless devices, cell phones, laptops — all of them beeping, ringing, flashing — they make demands on our time and our attention,” Forlizzi says. “That means that we have less time to do real knowledge work, and we spend more time on task work: answering messages and shuffling papers.”

One of Forlizzi’s least surprising observations: People are most prone to interruptions when they’re on the phone. One of her more surprising recommendations, especially in a no-frills economy: Don’t minimize the value of even a reasonably competent executive assistant. According to Forlizzi, M*A*S*H’s Radar O’Reilly may come to symbolize the unsung heroes of overworked, underresourced offices everywhere. Of course, Forlizzi is also working on high-tech devices designed to help solve the problem of unproductive interruptions, such as sensors and “smart” fabrics in furniture. By tying that information to hypotheses such as, “When people have their feet up on the desk, they are more interruptible,” Forlizzi hopes to make the workplace environment smarter about when people can and should be disturbed. It’s either that, or hire your own Radar.