Broadly, I had decided on the topic of attention and distraction, but I had to define attention, and how the topics of distraction, interruption, and focus related to it. I started my discovery process by reading a few books to get a foothold in the subject area.

I started with the book Rapt by Winifred Gallagher, where I found a frequently cited definition of “attention” from The Principles of Psychology by Henry James, published in 1890:

Everyone knows what attention is. It is the taking possession of the mind, in clear and vivid form, of one out of what seems several simultaneously possible objects or trains of thought. Focalization, concentration, of consciousness are of its essence. It implies a withdrawal from some things in order to deal effectively with others.
Gallagher, Rapt, 6.

Since James wrote his definition, modern neuroscience and and psychology have defined attention in more scientific terms. One such model was defined by neuroscientist Michael Posner, who described the attentional system of the brain as having three subsystems: alertness, orienting, and executive function.

Gallagher, Rapt, 64.

According to James and Posner, therefore, a significant component of our attention is our means to control it. Distraction can then be defined as a counter: a force against the control of our attention. In his book Distraction, philosopher Damon Young describes distraction from this more philosophical perspective:

...the good life warrants an ongoing struggle to be clear about what’s important, and to seek it with lucidity and passion; not to be distracted by false ambitions, or waylaid by dissipated consciousness. This conundrum is captured in the Latin root of the word distraction, meaning literally to tear apart of pull asunder. When we are distracted, we’re dragged away from what’s worthwhile.
Young, Distraction, 3.

Distraction is not a new concept, but recent technology has amplified the force of it. In his book The Shallows, author Nicholas Carr discusses the way the Internet has affected our attention and our control of it:

Our use of the Internet involves many paradoxes, but the one that promises to have the greatest long-term influence over how we think is this one: the Net seizes our attention only to scatter it. We focus intensively on the medium itself, on the flickering screen, but we’re distracted by the medium’s rapid-fire delivery of competing messages and stimuli. Whenever and wherever we log on, the Net presents us with an indelibly seductive blur.
Carr, The Shallows, 118.

In Distracted, author Maggie Jackson goes even further:

Attention is like a second skin, a meeting ground for our ever-present grappling with external and internal worlds. Yet used well and nurtured carefully, our networks of attention are our foremost means to shaping our lives. These networks give us extraordinary ways to master ourselves and our environment, offering the key to growth, connection, happiness. Accepting a culture of eroding attention relinquishes this potential for sculpting our individual and collective futures. ... Will we slip into a dark age of distraction?
Jackson, Distracted, 262.

I don’t know if we are on the threshold of a new dark age, but it is clear that the technology we created is having unintended effects on our ability to maintain our attention. The obvious question becomes, what can be done with it? Later in Rapt, Gallagher proposes one solution:

One crucial fact often gets overlooked in laments about the electronic assault on your ability to focus: your machines are not in charge of what you attend to – you are. When they prove distracting, you have only to turn them off.
Gallagher, Rapt, 162.

Gallagher is correct that people can opt out. To a large extent, however, people choose not to.

I think this is the point at which a designer can make a contribution to the field. It is not enough to say that a person can choose to stop using something we designed whenever they want to. We designed the systems that are distracting us, and the only way to make those systems less distracting is to design something better.