We live in a world of
distraction. When you sit at your
computer trying to write or work, there is a real danger that you will get
interrupted by an email, instant message, text message, or phone call. Even if you do your best to skip past the
distractions, there still may be a moment where you have to decide whether to
answer the phone or check your email.
What influence do those small
interruptions have on your ability to perform complex tasks?
This question was addressed in a
clever set of studies by Erik Altmann, Greg Trafton, and David Hambrick in a
paper in the February, 2014 issue of the Journal of Experimental Psychology: General.
To explore this question, the
researchers had to develop a complex task that would allow them to observe
errors. In this task, participants saw a
computer screen with a box in the center.
On each trial, there was a number and a letter. One of the characters was inside the box, and
one was outside. One character was
either in italics or had an underline.
One character was either red or yellow.
The character outside the box was either above it or below it.
The task required participants to
perform a sequence of different judgments in a sequence. To help participants remember the sequence,
the order of the tasks could be remembered by using the word UNRAVEL. For example, the first task (U) asked whether
a character was underlined or in italics.
On the next trial, participants did the N task (is the letter near or
far from the front of the alphabet).
Following that, they did the R task (is the colored character red or
yellow). Then A (is the character above
or below the box), V (is the letter a vowel or a consonant), E (is the digit
even or odd) and then L (is the digit more or less than 5). After doing the L task, the sequence returned
to U.
To respond to a particular task,
participants typed the first letter of the response on a computer
keyboard. So, in the U task, they typed
a U for underlined or an I for italics.
There are two interesting aspects
to this task. First, the sequence is
complicated. Second, the individual
tasks differ in how hard they are to perform.
Deciding whether a character is above or below the box is easier than
figuring out whether the letter is near or far from the start of the alphabet.
To look at interruptions, there
was a second task that happened periodically.
A box would appear on the screen with a code on it. The code was a few letters or numbers. They had to type the letters or numbers into
the box to continue the task. Some
participants got 4-character codes, while others got 2-character codes. That means that the interruptions were either
about 4-seconds long or about 2-seconds long.
These interruptions happened randomly about every 6 trials.
How did the interruptions affect
performance of the task?
These brief interruptions
influenced people’s ability to remember where they were in the sequence. People who got long interruptions (having to
type 4 characters) were about three times more likely to make an error on the
trial following the interruption than on trials with no interruption. People who got short interruptions (having to
type 2 characters) were about twice as likely to make an error on the trial following
the interruption than on trials with no interruption.
The errors caused by the
disruptions were sequence errors.
Basically, the interruptions caused people to lose their place in the
sequence. Most often, they mistakenly
did the task they had just did or did the one following the one they were
supposed to do in the sequence.
The results related to the
difficulty of the tasks were also interesting.
As I mentioned, some of the tasks were easier than others. This ease was reflected in the likelihood
people would make an error on that task.
For example, people made more errors on the near vs. far from the start
of the alphabet task than on the underlined vs. italics task. But, the effect of interruptions was the same
for easy and hard tasks.
Putting this all together, then, even
very short interruptions are particularly bad when people are performing tasks
that require a sequence of steps. The
interruption disrupts people’s ability to remember where they are in the
sequence, and so they are likely to carry out the wrong step following an
interruption.
Just one more reason to try to
keep your work environment free of even tiny distractions.
