How to be a disagreeable (but likable) robot

Driven to distraction
In a similar vein, Nass began wondering how emotional speech might affect drivers. “Happy people benefit from happy people,” he said, but what about the cliché that misery loves company? “Totally wrong,” Nass said. “It loves miserable company.”

In a series of experiments conducted in 2005, he and collaborators from Stanford and Toyota first showed drivers a five-minute video that left them feeling either happy or upset, then had them use a driving simulator for 20 minutes.

As a “passenger,” the researchers included a pre-recorded message from a woman offering both comments and questions about the route (“My favorite part of this drive is the lighthouse”). Half the time, her voice was energetic. The other half, it was subdued.

The experiment showed that already happy drivers drove best and conversed more when the upbeat-sounding voice was along for the ride. Sad drivers, however, preferred the subdued voice, as suggested by a decreased number of accidents during the simulation.

“For sad drivers, they were actually distracted by the happy voice,” Nass said. And when asked, they clearly preferred the voice that more closely matched their somber mood. “It tells us that voices in cars manifest more than just content, they manifest emotion,” he said.

Installing an emotion-laden voice into car technology could be inexpensive and easy to implement, he said. Ah, but which voice? Drivers are emotionally fickle creatures, and who would take the blame if a cloyingly perky computer navigator led a suddenly depressed driver to distraction — and into a ditch?

Simulating a wide range of emotion in speech programs has become a major area of research by both industry and academic groups. The catch, according to Nourbakhsh, is that synthetic speech is much further along than the ability of computers to model the cognitive states of humans and how to interact with them over time.

Automated call centers, for example, can be optimized so that an increasingly apologetic voice politely asks a misunderstood caller to try again. Perhaps the method could encourage more people to remain on the line instead of hanging up in frustration, but Nourbakhsh cautions that an over-reliance on the technique could hide deeper problems.

“We’re using an emotional short-circuiting to get over the fact that our voice-recognition stinks,” he said. “Do we really want to invent a back-story so that it’s OK for the robot to be wrong, when we really want to make them better?”

When the robot is actually right, communication can be even trickier. “It’s an interesting question as to when and how you should correct a human,” he said. “There are some obvious lines in the sand that you should draw.”

Trivial corrections are likely to quickly strain relations, but as the danger increases — a driver is driving the wrong way on a highway, for example — a robot would need to weigh the emotional impact on the driver against the consequences of not intervening.

The trick, Nourbakhsh said, is to make the system as cognitively nondisruptive as possible.

“In other words, if you’re kind of a quiet person and it blares at you, that’s bad.”

For toys, the dissonance may not matter. But until researchers find the proper balance, Nourbakhsh said, the use of voice — and especially of emotional voice — will likely proceed more cautiously in products like automobiles.

“It’s not going to be like Robin Williams in your car,” he said.

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