Human Responses to Technology Scrutinized

Similar techniques are being used to enhance teaching software -- by detecting when a student's interest is flagging.

The second, cruder approach involves encouraging people to believe that machines respond in social ways. The automated reservation systems used by Amtrak and many airlines fall into this category. When done right, said Clifford Nass, a professor of communication at Stanford University and a pioneer in understanding the ways people relate to machines, users go along with the deception. Done wrong -- when "Julie" cannot respond to a simple question, for instance -- people get even more frustrated than they would be with a machine that makes no pretense at being human.

"It turns out if 'Julie' speaks in that machine-like speech, people hate it when it says, 'I,' " Nass said. "They think it's clear you are not an 'I.' When it is recorded speech, people are more comfortable with the 'I' -- up to the point it fails them."

The second approach also plays on people's vanity. People usually prefer a spellchecker program that occasionally compliments them on getting a tough word right, Nass said.

Matching a person's personality with advertising messages might radically increase sales, Nass said. For instance, Amazon.com might sell more books if it found out whether a customer is an introvert or an extrovert by asking whether he prefers going to a party or reading a good book -- and then tailoring descriptions of products accordingly. Introverts tend to like factual messages; they distrust flowery language. Extroverts are the opposite, Nass said.

The researcher said that software can help students learn better when a virtual "teacher" is accompanied by a virtual "student." That way, Nass said, the "teacher" can occasionally direct questions to the virtual student, and the real student does not feel picked on all the time. And the virtual student creates an illusion of a classroom setting, in which the real student can receive praise from both the "teacher" and a virtual peer.

Such techniques, Nass said, are really no different than the routine deceptions in human interactions. "We spend enormous amounts of time teaching children to deceive -- it's called being polite or social. The history of all advertising is about deceiving. In education, it's often important to deceive people -- sometimes you say, 'Boy you are really doing good,' not because you meant it but because you thought it would be helpful," Nass said.

"When I go into Nordstroms, I am treated fabulously. Do those people really like me?"