What are the Effects of Getting Interrupted?


L. M. Carrier, 2009


It’s hard to get through the day without getting interrupted. It’s even harder than it used to be a few years ago because now we carry around devices that allow other people to interrupt us whenever they want. The cell phone and the text messaging service are two good examples. Almost everyone experiences interruptions negatively: although we don’t mind being interrupted now and then, constant interruptions are a source of frustration and irritation, especially when we are working on an important project with a nearing deadline. Psychologists and other researchers are studying interruptions and finding out a few things about how they affect us and about whether they can be controlled.


1. Interruptions at the wrong time can have serious consequences. For example, a study done with nurses found that interruptions were blamed for problems that occur while giving medications (Fry & Dacy, 2007). The researchers gave questionnaires to nurses working in London and found that 94% of the nurses agreed that being distracting while giving medication to patients had a significant negative effect on their concentration. The patients themselves were seen as being responsible for the worst distractions, followed by having to answer the telephone. Another example comes from the business world, where working on projects is often interrupted by having to attend a meeting. One study looked at the psychological effects of getting interrupted by meetings during a typical workday (Luong & Rogelberg, 2005). In the table below, you can see the psychological measures of being interrupted on the left under “Daily well-being” and the two measures of interruption on the right under the columns “Meeting frequency” and “Time spent meetings.” While there is a lot of technical information on this chart, you can see that having more meetings (hence, more interruptions) was significantly associated with increased fatigue and increased subjective workload (the numbers with asterisks beside them).




From Luong and Rogelberg (2005) (“Meetings and More Meetings: The Relationship Between Meeting Load and the Daily Well-Being of Employees”)


2. There are good times to be interrupted and there are bad times to be interrupted. Psychological and other research is showing that not all interruptions are the same. The timing and style of the interruption can influence how much of a negative effect it will have on you when you are trying to get work done. Much of this research is done with simulated tasks on the computer in a laboratory. Research is done this way so that the researchers can have complete control over the number and styles of the interruptions to the computer user. For example, McCrickard, Catrambone, Chewar, and Stasko (2003) had computer users perform a browsing task while also having to respond to preprogrammed interruptions from the experimenters. The researchers found that the style of interruption was important in determining which effects were seen on the computer user. For instance, an interruption that appeared as a moving ticker across the screen was found to be disruptive in some ways but not in others. In a different study, it was found that the timing of the interruption mattered. Participants in a study worked on one of three different computer tasks while sometimes receiving interruptions on the computer screen (Adamcyk & Bailey, 2004). The researchers conceptualized tasks as occurring as a series of subgoals or subtasks, and they predicted that interruptions would be less harmful when they occurred before or after a subtask and most harmful when they occurred during a subtask. In the chart below, you can see that self-rated annoyance and frustration increased when the interruptions occurred during the predicted “worst” times and were minimized when the interruptions occurred during the predicted “best” times for interruption.




From Adamcyk and Bailey (2004) (“If Not Now, When?: The Effects of Interruption at Different Moments Within Task Execution”)


3. The psychological process of interruption. Psychological research is discovering why interruptions might be bad for you. It has been known by researchers for some time that switching between tasks requires an extra “switch cost” that slows down our work on the tasks (see When Multitasking Goes Wrong). Researchers studying interruptions specifically have also been honing in on what the nature of those costs are. In one study, researchers measured the cost associated with being interrupted while playing an artificial computer game in the laboratory (Altmann & Trafton, 2007). The graphs below show that getting restarted on the computer game after the interruption takes extra time. The first action taken in the computer game (Serial Position 1) is slowed the most, followed by the next action, etc., until actions in the computer game begin to go back to taking the time they took before the interruption. The “recovery” process takes about 15 seconds. The authors proposed that performing a complicated task like a computer game requires a rich set of information to be in memory or available to the user while the task is being performed. Being interrupted by another task could make that information unavailable. The recovery process could reflect the reactivation or reloading of the information.




From Altmann and Trafton (2007) (“Timecourse of recovery from task interruption: Data and a model”)


There is a lot of research left to be done in the area of interruptions. If you have interesting experiences with interruptions or are interested in pursuing a project related to them, let me know. My e-mail address is lcarrier@csudh.edu.




The statements, views and opinions presented on this web page are those of the author and are not endorsed by, or do they necessarily reflect the opinion of California State University, Dominguez Hills.