Forget everything you think you know about the perils of multitasking. A growing body of research shows that multitasking makes you more productive. You heard me: Multitasking is good for you and your work.

There’s just one hitch. You have to do the right amount of multitasking. Too much causes productivity to plummet.

Chances are you’ve heard that multitasking prevents long periods of focus. It interrupts our thought process. Intuitively, you probably believe that’s true. And to some degree it is. The case for multitasking is actually rather complicated.

Multi-Tasking and Task-Switching are Good for You

First, it’s important to mention that by “multitasking” I’m referring to two things: doing two more or more things simultaneously and task-switching.

Multitasking used to exclusively have the first definition, to do more than one thing at a time. Here are a few examples:

• listening during a meeting while also checking email
• breastfeeding while grading papers
• drinking coffee while talking on the phone
• eating lunch while reading a book.

Now let’s talk about task-switching, which is also a kind of multitasking. Task-switching refers to bouncing between tasks, usually over a fairly short amount of time. More specifically, task-switching refers to not completing a task all the way through without interruption. A few examples of task-switching are:

• writing the first few sentences of an article, stopping to check email, and then resuming your writing
• brainstorming ideas for a visual concept, having a meeting with your boss about something else, and then sketching some of the ideas you brainstormed earlier.

One potential value of task-switching that’s often overlooked is that it stands in for taking a break, and we know that taking breaks is good for productivity. When we task-switch effectively, we are letting our brains rest from the job at hand while doing something else that’s still productive.

Researcher Ellen Rose (2011) sees this kind of multitasking among her students who work in online learning environments, such as Blackboard. When students work online, the entirety of the Internet, including their email, instant messaging apps, social networks, and click-bait articles galore are at their fingertips. But, as Rose writes, “these students are in the process of redefining attention and focus, such that even those who admitted to breaking away often from online learning activities, sometimes for five minutes or more each time, described themselves as ‘very focused.’ Distraction is also being reconceptualized as not a hindrance to learning but a necessary diversion, and therefore a positive aspect of online learning.”

One of her students, in a survey, explained how multitasking pays off: “I find the multitasking ability that online learning allows you to do keeps me working for longer than if I couldn’t.”

Put another way, multitasking can increase productivity.

Certain types of multitasking are often overlooked, too. For example, let’s say you send a document to a colleague for comments and expect a quick turn-around, maybe five or ten minutes. Multitasking would mean doing any other task at all during the wait time. If you weren’t multitasking, you’d be sitting there waiting, keeping your mind fresh to pounce on the file the moment your colleague returned it. Making use of so-called downtime is one of the most efficient ways we multitask.

But even when we make use of true downtime, there’s a limit to the value of multitasking.

Show Me the Evidence!

Some good data back up this claim that multitasking is in fact productive. When productivity and multitasking are graphed, several studies find show an inverted-U shape. In other words, it’s highly unproductive to do no multitasking whatsoever (the bottom of the upside down U), and it’s highly unproductive to multitask too much (the far right of the inverted U). But there is a sweet spot in the middle where a little bit of multitasking causes productivity to skyrocket.

One of my favorite pieces of research on this topic comes from a hospital’s emergency department, where Diwas KC (2014) collected more than 146,000 records of patient discharges over three years. KC looked at how fast patients were discharged as well as patient outcomes (how often patients were readmitted to the ER within 24 hours of discharge). When a doctor sees a patient, she or he is never with that patient for an uninterrupted stretch of time until the patient is discharged. Doctors always have multiple patients. They also have fixed salaries, meaning they are not monetarily incentivized to see as many patients as possible.

Every patient typically comes with some downtime in the form of waiting for test results, and doctors use that downtime to swing back to other patient. This patient-juggling is classic multitasking. If a doctor were to see only one patient, uninterrupted, from admittance to discharge, it would be a hugely inefficient way to run an emergency department, and indeed, the data reflect just that.

KC found that the optimal number of patients to see at a time was around four to five. Four was the optimal number of patients to see to optimal results in patient revisits, while five was the target for getting the best discharge speed. The number of patients discharged per hour dropped when doctors had more than five patients.

What About Office Drones, er, Knowledge Workers?

Knowledge workers, of course, aren’t doctors, but they often juggle projects in the same manner that doctors juggle patients. They complete some aspects of a project, send it to another colleague, and use that downtime to work on a different project.

There just happens to be research on knowledge workers and multitasking, too (Aral, 2012), and it finds the same inverted U-shape pattern in productivity. In this study, researchers were interested in the very detailed practices of knowledge workers, specifically their use of technology. Older studies showed whether technology use increases productivity, but not how. This study looked at head-hunters, or executive recruiters. Their productivity is easier to measure than many other information workers’ because it comes down to whether they filled a job and how long it took.

Recruiters had their email use monitored and also answered surveys and were interviewed to find out more about their activities, skills, and behaviors. The recruiters use a special database to manage possible job candidates, called the Executive Search System (ESS). One of the primary findings was that “an inverted-U shaped relationship exists between multitasking and productivity such that, beyond an optimum, more multitasking is associated with declining project completion rates and revenue generation.”

In both the studies, the researchers mention that the optimal amount of multitasking likely varies by person, the type of job they do, and other factors. But on the whole, some amount of multitasking is more productive than none at all.

There are cases in which completing projects from start to finish without any multitasking may be more efficient and productive, but it depends on the job and the goal. Coviello et al. (2012), for instance, developed a model to prove that finishing one project at a time rather than juggling projects can speed up the average completion time. Their dataset comprised Italian judges moving cases through the system. Judges who open a case and don’t work on other cases until they close the first one have shorter completion times than judges who juggle cases. However, as I’m sure many knowledge workers will agree, that method of working consecutively is impractical in many situations.

References

Aral, S., Brynjolfsson, E., Van Alstyne, M. (2012). Information, technology, and information worker productivity. Information Systems Research 23(3-Part-2) 849–867.

Coviello, D., Ichino, A., and Persico, N. (2012). Time Allocation and Task Juggling. November 2012. American Economic Review. 104(2): 609-23. DOI: 10.1257/aer.104.2.609.

KC, Diwas (2014). Does Multi-Tasking Improve Performance? Evidence from the Emergency Department. Manufacturing & Service Operations Management. 16:2, 168-183.

Image by ericparker, CC.