Q&A with Alex Pentland
Yr cel knws what u wil do tonight
THREE YEARS AGO, Alex "Sandy" Pentland huddled in front of a computer, predicting the future.
On his monitor, he could follow the behavior of 100 students and faculty members as they traveled around the MIT campus; he could also see projections of what each person would do next. Over several months, as each of the subjects scurried from class to dorm to coffee shop, their cellphones beamed back moment-by-moment updates to Pentland's lab. After he had crunched the numbers, he came up with a kind of fingerprint of each person's weekly routine. Pentland and his colleagues could pick out any one student and guess - often with an 80 to 90 percent accuracy rate - whether that person was about to head to the gym, go home, or meet her boyfriend for dinner.
And when the researchers looked at all the routines together, they could make inferences about the behavior of groups. For instance, they could figure out which students considered each other true friends, and which ones spent time together only because they had to complete a project.
The study took advantage of the enormous power of cellphones to report on their owners' activities. Creepy, yes. But in this case, the MIT students wanted to be spied on; as volunteers for the study, the largest of its kind ever conducted in a university setting, they agreed to donate their cellphone logs to the researchers. To make his snapshots even richer, Pentland - a professor of media arts and sciences - also loaded the phones with special software that monitored tone of voice.
He will describe several of his cellphone studies in his book "Honest Signals," coming from MIT Press this fall.
IDEAS: How did you come up with the idea for the study?
PENTLAND: Back in the 1990s, people began talking about computers getting smaller. It occurred to me that if they were going to get small they'd be built into your buttons and eyeglasses. So I started doing "wearable computing" research with a bunch of students who ran around wearing computers.
IDEAS: The cyborgs! I remember them. They had laptops on their backs and special eyeglasses so they could surf the Web while they walked around Cambridge.
PENTLAND: Yeah. Those were my guys. And so then computers really did get small; they turned into cellphones, and now we can have incredibly intimate portraits of ourselves because of these devices. They record where we are and who else is around; they record the sound. It's like your memory. They remember where you've been. For the first time, you can view people's lives in this intimate way. Of course, then I realized that everyone has a cellphone, and that this could provide a "God's eye view" of humanity.
IDEAS: What most surprised you about this study?
PENTLAND: What most surprised me was how predictable people are. How easy it is to read them. You can tell when a group is overloaded. You can tell when someone is depressed.
It's spooky. If I see the pattern of how you get up in the morning and go to work, I can predict what you're going to be doing at 5 p.m. - and whom you're going to be doing it with.
IDEAS: Could my cellphone company collect all of this information from me without my knowing it?
PENTLAND: Well, that's an interesting question. Currently the company collects the data but doesn't look at them because of legal and privacy issues.
IDEAS: Cellphones present us with a dilemma, because the more they know about us, the better they serve us. But as phones get smarter, they increasingly threaten our privacy.
PENTLAND: Exactly. We need to come up with a new way of being private in a world where there are sensors everywhere. If we're going to stop global warming or SARS, we have to be able to see our world clearly and quickly, and we have to be able to react. You could do amazing things with cellphone data. The trouble is, no one person wants to be under the microscope.
IDEAS: You've written about one of the cellphone's most surprising capacities: It lets us spy on ourselves, by looking back at our "life logs" - who we called, where we went. Do you use your cellphone as a mirror to examine your own behavior?
PENTLAND: Yes, I use it as reflection aid. What's particularly useful is when [the data] tells me, "You know, you're acting a lot crazier than usual. Maybe you better go on vacation. Spend some time with your kids." I'm trying to build tools that will help all of us understand ourselves better.
IDEAS: Have your cellphone logs helped you to predict your own behavior?
PENTLAND: Well, it's helped me learn how I sound. We wrote software that analyzes the tone and rhythm of voices, and we load this into cellphones to give people a sense of how they sound in social situations. For instance, one thing you can tell is whether people are paying attention. It has to do with timing [in the conversation]. You may have heard this rumor that husbands tend not to listen to their wives. So we built this thing we call the Jerk-O-Meter, which listens in the background as you talk to your wife and gives you a "jerk" rating if you sounded like you weren't paying attention.
IDEAS: But how do you tell whether the Jerk-O-Meter is correct? Did the rating go up when you really were bored with the conversation?
PENTLAND: Yes, exactly. You know, it's sometimes not the big cosmic issues that matter the most. The real question may simply be, "Are you paying attention to the people you care about?"
Pagan Kennedy is the author of nine books, most recently "The First Man-Made Man." She can be reached through her website, pagankennedy.net.
