When was the last time you were interrupted in the middle of an important conversation or writing an email, completely derailing your train of thought? It happened to me twice just as I wrote this piece.

Impact of Interruptions

Observational studies have shown that workers are typically interrupted more than 12 times per hour in their work environment. These interruptions cost companies an estimated $588 billion a year.

Unfortunately, interruptions affect us all—at work, home, and anywhere in between. The surge in communication-based technologies over the past few decades has increased the number and type of interruptions, such as email and cell phone calls, that afflict us.

Traditionally, people have focused on the issues of time and error to measure how disruptive interruptions can be. This makes sense. The time lost to interruptions or the errors made (such as skipping a step) are easily identified and measured. However, time and error are not always the best way to measure the impact an interruption has on performance.

For example, if a student is writing an essay for school, a five-minute interruption to assist a friend may not matter, assuming the delay doesn’t cause the student to miss a deadline. However, if the quality of that essay suffers and the student receives a C+ instead of an A, the interruption has had a measurable effect on the student’s performance.

Case in point

This was the basis for a new line of research being explored at George Mason University – how do interruptions affect performance beyond time and error? A recent study published in the journal Human Factors, showed that interruptions affect the final quality of essays when writers are interrupted.

Specifically, three one-minute interruptions took place either while students were outlining or writing an essay. The interruptions reduced the final quality of the essays by approximately .5 point overall, using a 6-point scale designed by The College Board to assess essay quality on the SAT. More important, the interruptions also caused students to write fewer words in their final essay when they were interrupted during writing, even though they were provided with additional time to compensate for the time lost to the interruptions.

This was the first study to show that interruptions directly reduce performance as indicated by quality of the work. Further, almost all of the participants were negatively affected; more than 90 percent of participants’ scores were lower when they were interrupted than when they were not interrupted.

You might wonder how the interruptions reduce the quality of the essays. The reduction in word count suggests that the interruptions are disrupting the thought process and leading to fewer ideas being generated. Analyses of the outlines and follow-up studies suggest that participants are, in fact, not fully developing their ideas after being interrupted.

Indeed, it appears that many participants fail to fully develop the idea they were working on prior to the interruption when they come back to the outline. Instead, they seem to move on to the next major discussion point. This could be thought of as a triage effect, moving on to the next major point or next meaningful thought instead of finalizing the smaller, more nuanced discussion points.

Moving Forward

From a practical standpoint, the obvious question is: What can be done to avoid the disruptive effects of interruptions? A simple, but unrealistic solution is to avoid being interrupted.

Although it is difficult to avoid all interruptions, you can take steps to reduce the number of interruptions.  You can silence your phone, disable notifications (like Facebook and text messages), and shut your door. If you know an interruption is coming, such as a colleague is heading over to get you for lunch, or you desperately need to check your email, find a good stopping point.

In other words, attempt to finalize whatever step of the task you are working on. If reading, finish the section or chapter instead of stopping mid-sentence. If writing, try to finish the section you are working on. Also, mark the spot where you left off and write down any remaining ideas or thoughts running through your head so you can be reminded of those when you return to the task later.

Although these measures won’t guarantee that you won’t be interrupted or that the quality of your work won’t suffer, they are the best solutions to this pervasive problem at this time.

Additional Resoources

Cades, D. M., Werner, N. E., Boehm-Davis, D. A., & Arshad, Z. (2010, September). What makes real-world interruptions disruptive? Evidence from an office setting. In Proceedings of the Human Factors and Ergonomics Society Annual Meeting (Vol. 54, No. 4, pp. 448-452).

Foroughi, C. K., Werner, N. E., Hatcher, M. C., Lopez, A. J., Zafar, T. W., & Boehm-Davis, D. A. (2014, September). Do Interruptions Affect Content Production?. In Proceedings of the Human Factors and Ergonomics Society Annual Meeting (Vol. 58, No. 1, pp. 255-259).

Foroughi, C. K., Werner, N. E., Nelson, E. T., & Boehm-Davis, D. A. (2014). Do Interruptions Affect Quality of Work? Human Factors: The Journal of the Human Factors and Ergonomics Society, 0018720814531786.

Spira, J. B., & Feintuch, J. B. (2005). The cost of not paying attention: How interruptions impact knowledge worker productivity (Technical Report). New York: Basex.