The Science of Interruptions In 2000, Gloria
Mark was hired as a professor at the University of California. She would arrive
at her desk in the morning, full of energy and ready to tackle her to-do list.
No sooner had she started one task than a colleague would e-mail her with an
urgent request; when she went to work on that, the phone would ring. At the end
of the day, Mark had accomplished a fraction of what she set out to
do. Lots of people complain that office multitasking drives them
nuts. But Mark studies how high-tech devices affect our behavior, so she was
able to do more than complain: She set out to measure how nuts we’ve all become.
She watched cubicle (办公室隔间) dwellers as they surfed the chaos of modern office
life and found each employee spent only ten-and-a-half minutes on any given
project before being interrupted. Each short project was itself fragmented into
three-minute tasks, like answering e-mail messages or working on a
sheet. Mark’s study also revealed that interruptions are often
crucial to office work. The high-tech workers admitted that many of their daily
distractions were essential to their jobs. When someone forwards you an urgent
e-mail message, it’s often something you really do need to see; if a mobile
phone call breaks through, it might be the call that saves your hide. For
some computer engineers and academics, this realization has begun to raise an
attractive possibility: Perhaps we can find an ideal middle ground. If high-tech
work distractions are inevitable, maybe we can re-engineer them so we receive
all of their benefits but few of their downsides. The Birth of
Multitasking The science of interruptions began more than
100 years ago with the emergence of telegraph operators — the first high-stress,
time-sensitive information-technology jobs. Psychologists discovered that if
someone spoke to a telegraph operator while he was keying a message, the
operator was more likely to make errors. Later, psychologists determined that
whenever workers needed to focus on a job that required the monitoring of data,
presentation was all important. Using this knowledge, cockpits (驶舱) for fighter
pilots were carefully designed so that each dial and meter could be read with
just a glance. Still, such issues seemed remote from the lives
of everyday workers. Then, in the 1990s, computers began to experience a rapid
increase in speed and power. "Multitasking" was born; instead of simply working
on one program for hours at a time, a computer user works on several
simultaneously. Office workers now stare at computer screens of overwhelming
complexity, as they juggle (操纵) messages, text documents, PowerPoint
presentations and web browsers. In the modern office we are all fighter
pilots. Effect of Multitasking: Computer-affected
Behavior Information is no longer a scarce resource —
attention is. 20 years ago, an office worker had two types of communication
technology: a phone, which required an instant answer, and postal mail, which
took days. Now people have dozens of possibilities between these two
poles. The result is something like "continuous partial
attention", which makes us so busy keeping an eye on everything that we never
fully focus on anything. This can actually be a positive feeling, inasmuch as
the constant email dinging makes us feel needed and desired. But what happens
when you take that to the extreme You get overwhelmed. Sanity lies in
danger. In 1997, Microsoft recruited Mary Czerwinski, who once
worked in NASA’s Human-computer Interaction Lab, to conduct basic research to
find out how computers affect human behavior. She took 39 office workers and
installed software on their computers that would record every mouse click. She
discovered that computer users were as restless as hummingbirds. On average,
they juggled eight windows at the same time. More astonishing, they would spend
barely 20 seconds looking at one window before flipping to another.
Why constant shifting In part it was because of the way computers are
laid out. A computer offers very little visual real estate. A Microsoft Word
document can cover almost an entire screen. Once you begin multitasking, a
computer desktop quickly becomes buried in windows. When someone is interrupted,
it takes just over 23 minutes to cycle back to the original task. Once their
work becomes buried beneath a screenful of interruptions, office workers appear
to forget what tasks they were originally pursuing. The central danger of
interruptions is not the interruption at all, but the confusion they bring to
our short-term memory. Ways to Cope with Interruptions
When Mark and Czerwinski, working separately, looked at the desks of the
people they were studying, they each noticed the same thing: Post-it notes.
Workers would write brief reminders of the task they were supposed to be working
on ("Test DA’s PC, Waiting for AL... "). Then they would place them directly in
their fields of vision, often in a circle around the edge of their computer
screens. These piecemeal efforts at coping pointed to ways that
our high-tech tools could be engineered to be less distracting. Czerwinski also
noticed many Microsoft people attached three monitors to their computers. They
placed their applications on different screens — the email on the right side, a
web browser on the right and their main work project in the middle — so that
each application was read at a glance. When the ding on their email program went
off, they just peek to the left to see the message. The workers
said this arrangement made them feel calmer. But did more screen area actually
help with cognition To find out, Czerwinski had 15 volunteers sit in front of a
regular size 38 cm monitor and complete a variety of tasks designed to challenge
their concentration — a web search, some cutting and pasting, and memorizing
phone numbers. Then the volunteers repeated the tasks using a computer with a
massive 105 cm screen. On the bigger screen, some people
completed the tasks as much as 44% more quickly. In two decades of research,
Czerwinski had never seen a single change to a computer system so significantly
improve a user’s productivity. The clearer your screen, the calmer your
mind. Looking for Better Interruptions Mark
compared the way people work when sitting in cubicles with how they work when
they’re at different locations and interact online. She discovered people
working in cubicles suffer more interruptions, but they have better
interruptions because their co-workers have a social sense of what they’re
doing. When you work next to others, they sense whether you’re deeply immersed
or relatively free to talk and interrupt you accordingly. Why
don’t computers work this way Instead of alerting us to email messages the
instant they arrive, our machines could deliver them at optimum moments, when
our brains are relaxed. Eric Horvitz at Microsoft is trying to do precisely
that. He has been building automated reasoning systems equipped with artificial
intelligence that observes a computer user’s behavior and tries to predict the
moment the user will be mentally free and ready to be interrupted.
(1,161 words) As Mark’s study indicated, interruption is a highly undesirable feature in high-tech office work, and therefore we must find a way to avoid them.