Cynthia Breazeal

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reazeal played an active role in building Kismet. Drawing on her experience helping build two prior complex robots, she worked on everything from the mechanized design for Kismet's facial features to tinkering with its body parts in the shop. Breazeal took great care with the robot's facial features, which she considered important to making it an appealing social actor. She found a special-effects expert to make human-like eyes and personally glued on false eyelashes purchased in a beauty-supply store. And she put bright red lips on its metal mouth, using surgical tubing colored in with a red pen.

Body Parts
Kismet has an array of built-in features that help it act in a human-like way. It has four color cameras that allow it to "see," and its computers are programmed to help it recognize objects and measure distances. Kismet seeks out colorful toys and faces actively. It recognizes faces by looking for flesh tones and eyes. Kismet can hear, but only when humans speak into its microphone. And Kismet has motor capabilities that allow it to shift its eyes and crane its head toward particular sights and sounds. One of the robot's best features is its ability to register expressions that correspond to its emotional state. When it is surprised, it can raise its eyebrows. When it is sad, it can frown. Kismet can also vocalize, in a sing-song babble. In January, it said its first words: "[][ch'ao<186>][el'ao<139>z] ['aa<138>rr<109>]." It wasn't "Mama," but Breazeal was proud enough to put it on Kismet's website.

Kismet was designed with motivational drives, drawn from developmental psychology. A computer attached to the robot displays bar graphs that reflect its three drives--social, stimulation and fatigue. Kismet's desire to satisfy these drives leads it to engage in a variety of purposeful behaviors, much as a human baby would. When its social drive is high, indicating that it is lonely, the robot actively seeks out human interaction. When its stimulation drive is high, it is drawn to other forms of interaction, including playing with colorful toys. Since it has no arms, it can't pick up a toy itself. But if it stares plaintively at a toy, a nearby human will usually pick it up and bring it over. When Kismet has had enough stimulation, its fatigue drive kicks in.

Kismet is able to engage in the kind of purposeful human interactions that cousin Cog could not. Kismet calls people toward it. And when they get too close for its cameras to see them well, it protects its personal space and pulls away. When an object suddenly appears in front of it, Kismet quickly withdraws

and flashes a look of bewilderment. Most winningly, the robot is able to engage in a babbling "conversation" with humans in its midst. When it "talks," it takes turns with its human interlocutor, a decent representation of a conversation between an adult and an infant. By one measure, Kismet is a clear success: people love it. When visitors arrive in the lab, they are drawn to the robot. When Kismet engages them, they are invariably charmed. "It's human nature," says Breazeal. "They are very concerned about keeping it happy." Proof of its winning personality: a box of toys given to it by human friends, including a yellow teddy bear sent from Japan.

The Urge to Invent
Breazeal is attracted to inventing because it is hands-on and real-world. "I would much rather build something and interact with it than philosophize about it," she says. "Or philosophize about someone else doing it." But at the same time, she has used robotics to explore some subtle intellectual issues. At M.I.T., Breazeal has studied brains and cognitive science, and her work with Kismet raises complex issues about how humans think and learn.

In designing Kismet, Breazeal made a critical decision about how she wanted it to develop. There are two rival schools about ways to build robots. One holds that robotmakers should decide in advance what knowledge and skills they want their robots to have and then program them accordingly. Breazeal has a different view. She thinks robots should be designed to learn from experience and from their environment. This socially situated learning, as it is called, allows Kismet to learn much like a human baby would.

The problem is, robots have fewer opportunities than babies to learn from their environment. Humans spend a great deal of time talking to and nurturing young people. Robots do not get that kind of attention and outside stimulation. "We don't learn in impoverished educational environments, but that's what we expect the robot to do," she says. Breazeal has tried to provide Kismet with the tools to engage in this kind of socially situated learning.