Collaboration & workplace interruptions

Recently I have been thinking a lot about the impact of collaborative tools on workplace interruptions.

In the old days of computers, PCs could only work on one task at a time. This naturally discouraged task switching, since there was a cost of setting up and quitting the application. Instead, people completed the task they were on before moving on to the next one.

Not coincidentally, this habit also closely mirrored the traditional "in-tray" approach of business. Take the first piece of paper; deal with it; move on to the next. The only difference was that it encouraged "clumping" of tasks. Deal with all tasks requiring Application A, then move to all those requiring Application B.

Once multitasking became widespread with Windows 3.1, this approach no longer had to hold. People could partly complete one task; switch to another task on demand; and switch back. However, my memory of these early days is that multi-tasking was generally reserved for reference purposes. You might run multiple windows, but generally the new task supported the completion of the original, "master" task.

The advent of email and the internet changed all that.

A recent study by Gloria Mark showed that information workers switched activity, on average, every three minutes and five seconds. What's more, roughly half of these switches happened without any external trigger. In other words, we have become workers driven by interruption.

Gloria made two other significant discoveries. First was that interrupt-driven work is more stressful. Not particularly surprising, given the constant cognitive shifts required to change task. However, she also found that people who were not interrupted worked at a slower pace. Interruptions encourage people to work in "bursts" -- to focus intently on a task until the next "switch".

"Switching" may occur for a number of reasons: boredom, frustration or time-based prompting. However, if productivity on the current task is already low, then a brief switch to a new topic may lead to a net increase in productivity on the original task over the longer term.

So the trick is to distinguish non-productive switches from productive switches. A number of studies have demonstrated that switches to a completely different subject matter are very damaging to productivity. This is due to the "switch time" -- the time it takes to cognitively switch gears and start thinking about a new problem.

On the other hand, working on several similar tasks may provide the cognitive boost of the switch without as much damage caused by gear-switching. Low-level cognitive tasks which don't require deep thought can also be achieved without a big decline in productivity.

This leads to the conclusion that it is the ability to control interruptions that is most important. When people are given the ability to defer or ignore an interrupt request, they can maximise their productive working time on a certain task or cognitive area of thought before switching.

When email first became common in businesses, many managers were wary of the wrong thing. Wouldn't people always spend time emailing their friends and wasting time? And yes, this did happen, but the productivity benefits so greatly outweighed the costs (particularly for things like exchanging documents as attachments) that the grumbles disappeared.

However, the more important impact was not predicted. Once people became always connected to a world outside their own, the temptation to check if an interrupt was available was almost irresistible.

This phenomenon of the compulsive checker is found over and over again, but most recently is seen in Facebook -- where people are known to check if their page has updated dozens of times a day.

Email notification pop-ups are often seen as problematic, in that they encourage users to switch tasks. However, the opposite is more likely to be true: when users are given indicators of when potential interruptions arrive, they also know when no interruptions are waiting.

This reduces the need for users to interrupt just to check for interrupts. Similar productivity arguments can be made for the use of IM and RSS subscriptions, which both make the promise to the user -- "when we have something to tell you, you'll be the first to know".

And in an environment where people ultimately choose what will get their attention, that promise is an important part of maximising productivity.