IEEE Spectrum December, 2012 - 35

casts its location ID; beacons are strategically placed around
the space that's being monitored-on conference room tables,
users' desks, and so on. Each badge's small LCD screen displays the time, temperature, the number of other HBM wearers you've met that day, and how physically active you've been.
The badge also collects information about the types of
exchanges that take place. For example, sitting with colleagues
in a conference room listening to a presenter drone on for hours
is very different from having an animated conversation around
the coffee machine. The HBM can discern that difference, again
by monitoring people's movements and measuring the energy
level of their voices.
Before leaving the office each day, a user places the badge in
a "cradle," which recharges the battery and also downloads the
stored information. These measurements are transmitted over
the Internet to Hitachi's data center for analysis and long-term
storage. Periodically, the system provides users with reports
on the activities that are being monitored.
Since the HBM's introduction three years ago, hundreds
of organizations, including banks, information service companies, design firms, research institutes, call centers, and
hospitals, have used it to collect about 10 terabytes of behavioral data, amounting to half a million person-days. Of course,
understanding people's subjective experience requires more
than just recording how they move or to whom they talk. And
to make sense of all those data, you need a scientific framework
of human behavior.

much as a pedometer counts a person's steps. That is, the accelerometer measures each motion in the x, y, and z axes. Later those
measurements are translated into a single value that indicates
the degree to which you are moving about in space.
The sensor can tell when two or more wearers are in close
proximity using its six infrared transceivers, which point in
different directions to cover a wide area in front and to the sides
of the wearer. When these transceivers detect another badge
within 2 meters, the two badges exchange IDs. Each badge then
records the time, duration, and location of the interaction. To
determine location, the badge listens for signals from the nearest "beacon," an infrared apparatus that constantly broadspectrum.ieee.org

each person has his or her own motivations, feelings, and
goals-all of which affect behavior. But these underlying factors may not necessarily be apparent to casual or even trained
observers. Does a person's erratic movements indicate distress or giddiness? Do fewer than the normal number of social
interactions one day mean that a person is depressed, or just
engrossed in an engaging activity? Engineers need a way of
distilling sensor data into meaningful mental states.
For that, we turn to the emerging field of positive psychology. Unlike traditional psychology, which focuses on problems-stress, depression, anxiety, obsessions, and mood
swings, to name a few-positive psychology looks at desirable
mental states (including happiness) and sought-after character
traits (such as self-control and generosity), as well as the internal and external factors that contribute to well-being.
You might think that happiness is something ineffable, an
elusive state of being that defies quantification and analysis.
But over the past decade, one of us (Lyubomirsky) and her collaborators at the University of California, Riverside, have conducted many studies that demonstrate that happiness can, in
fact, be systematically measured.
These findings can be counterintuitive. For example, most
of us tend to believe we will be happier when we marry, buy
a house, or get a raise. It turns out, though, that such external circumstances contribute in only a small way to our longdEcEmbEr 2012 * iEEE SpEctrum * NA

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Table of Contents for the Digital Edition of IEEE Spectrum December, 2012