Multitasking (Part 2 of 3): The Mechanics of Multitasking
by H. Les Brown

Imagine yourself reading your mail, deciding how to respond to a client's letter. A colleague enters your office with a question regarding an important report she is writing. In the midst of that conversation, the phone rings.

This second article of a three-part series on multitasking will discuss the mechanics of task switching and its consequences. The first article clarified that multitasking is actually rapid, serial task switching, and the third will consider ways that coaches can best manage their own tasks and help their clients manage theirs.

How Does Multitasking Work?
'Stimulus identification' is the first step in the task-switching process. When you are interrupted, you must interpret the interruption in the context of previous learning and experiences. Cues in the environment (e.g., your colleague enters your office, the phone rings) require that you reorient yourself by asking, "Where was I?"
Next, you must determine the steps required to complete the new task. This 'response selection' process begins with goal shifting. Assume you've answered your colleague's question regarding the report. Your goal was to give her some necessary insight. When that goal is accomplished, you replace it with a different one.

Your new goal may be to handle the letter you were reading when your colleague interrupted you. To activate your new goal, you must 'unload' the procedural rules required by the previous task, and 'load' the series of learned procedures or 'rules' relevant to the new task. With the rules for processing letters in place in your working memory, you're ready to act.
'Movement production' is the third step in the task-switching process. Your rules dictate four choices when handling a letter: 1) throw it out; 2) refer it to someone else; 3) file it; or 4) answer it. The rules provide you with guidelines for evaluating information and deciding how to handle the task at hand. You apply the rule, process the letter, and move on to the next task.

This three-step process takes time—a half-second or more per task switch The effects are cumulative: The more frequent the task switching, the larger those time gaps become. Consider what happens when you make a cell phone call while driving. Although you're nominally aware of the road, you must switch tasks twice—once to make the call and once to refocus on the road. In a sudden emergency, that's plenty of time to turn a 'near miss' into a fatal accident.

For Better Or Worse

A number of task-related factors affect our ability to switch tasks quickly and effectively:

  1. Perceptual cues;
  2. Operational complexity;
  3. Rule set size;
  4. Task dominance;
  5. Task familiarity;
  6. RSI (response-stimulus interval);
  7. Attention span; and
  8. Cognitive patterns and styles.

You're working and your phone rings. While perceptual cues (#1) such as this may invite you to switch tasks, other perceptual cues actually bypass the thought centers entirely and go directly to the 'fight, flight, or freeze' response. For example, if you're walking alone at night and something flies out at you from the shadows, there is no invitation—you immediately fight, flee, or freeze.

Now imagine that you're writing a letter. A fly lands on you. You swat at it and return to your letter. This simple operation is minimally disruptive. However, the higher the task's operational complexity (#2), the more time it will take to switch tasks. If you're trying to solve a complex budgetary problem and your supervisor appears with a critical administrative issue, it might take you several minutes to switch tasks—in both directions. Task switching between complex operations also increases the probability of errors.

Let's examine rule set size (#3). You're concentrating on something and suddenly have to sneeze. Your hand moves to your mouth. The operative rule set is: 'Cover your mouth when you sneeze.' This is a simple rule set and doesn't break your focus.

A large rule set has the opposite effect. If you're building a complex spreadsheet and suddenly a co-worker bursts in with a question, you must switch your attention from the spreadsheet to your associate. You must then 'unload' one set of rules from your procedural working memory before 'loading' a new set of rules. The probability of experiencing confusion both when you turn your focus from the spreadsheet to the associate and when you finally return your focus to the spreadsheet is high.

Task dominance (#4) helps you determine when to shift tasks. You're composing a report that has to be finished by the end of the day. The phone rings, but you ignore it. A friend walks by, but you don't acknowledge him. The fire alarm blasts, and you shift tasks immediately. The more high-dominance tasks you face, the more frequent your task shifting.

Task familiarity (#5) speeds switching. Habitual behaviors can bypass conscious thought centers, and eventually you perform such tasks without giving them any attention. However, performing activities by rote can create inflexibility in behavior and can actually increase response time to new perceptual cues. If you're not paying attention to what you're doing, you're likely to miss important cues and continue rote activity inappropriately.

How does it feel to work under the pressure of a deadline? Even Ben Franklin quipped, "Haste makes waste." Now we know why. Decreasing the response stimulus interval  (#6)—the interval between one operation and the next perceptual cue—increases the rate of task switching. This ups the proportional amount of time spent in the switching process, thus decreasing both efficiency (speed) and effectiveness (accuracy).

Conversely, how do you cope with boring tasks? The tremendous increase in perceptual stimulation over the last generation (triggered by the popularity of video games and the rapid-fire visual images pioneered by MTV) has significantly decreased attention span (#7) in young people. Since many youth aren't accustomed to extended concentration (focus), they engage in unnecessary task shifting, and suffer all the attendant drawbacks—wasted time, wasted effort and decreased accuracy.

Some people seem to handle multiple tasks with comparative ease, while others struggle. These differences can be attributed to variations in cognitive abilities or styles (#8). 'Field independent' individuals are extremely focused and require high levels of perceptual cues to trigger task switching, while 'field dependent' individuals are more consistently aware of environmental cues, switching tasks more readily and with less effort.

Regardless of which combination of elements affects our capacity for task switching, we can draw an obvious conclusion: The more difficult, complex, unfamiliar, important and time-critical the task, the more damaging task switching is to efficiency and effectiveness.

What may not be so obvious is the damage task switching does to the individual him- or herself. Research has shown that frequent task switching diminishes a person's capacity for imagination and creativity—those critical intangible characteristics that define the most valuable members of a work team. In the long run, trying to multitask benefits neither workers nor the organizations that employ them.

H. Les Brown, MA, CFCC, Researcher for Business Coaching Worldwide and co-founder of ProActivation, is an innovator and change strategist who helps clients to effect deep and lasting change in their personal and professional lives. Read more about Les in the WABC Coach Directory. Les can be reached by email at

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