Multitasking and its effect on Performance

Multitasking is about switching focus between one task to another.  It then requires the person who is multitasking to regain focus, which could take between ten or fifteen minutes.  As can been seen, while multitasking causes the person to refocus, it also causes a loss in performance.   For example, Buser and Peter (2012) examined the performance level of males and females ability to multitask.  Another study examined judges who worked on many cases at once.  Those who worked on many cases at a time, performed worse as they took more time to complete their work compared to judges who scheduled their cases and worked sequentially.  One possible cause to decreased performance due to multitasking is the “task carryover account” meaning that there is a carryover effect when you switch tasks.  The carryover effect is a cost from the person needing to inhibit the previous information in order to complete the new task.  However, if the person had instead scheduled his or her task to be completed sequentially then the carryover effect would be eliminated causing an increase in productivity. 
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To put this in another way, when a person starts one task and then switches over to the next, while the first task is not fully completed then the activation of attention necessary to complete the second task takes longer as the first task is not fully uninhibited from the person’s attention span, producing a carryover effect.  Moreover, the mind of the person is still learning from the previous task and needs to prepare for the next task causing a cost (time) from switching from one task to the other.  In the Buser and Peter (2012) study, researchers found that the more people switched from one task to the other, the more performance suffered.  

It is important to mention that the studies discussed in this article investigated mental tasks, not physical tasks such as housecleaning.  Therefore a drop in performance may also have been caused by less mental processing as the ability to multitask requires bottom up processing (taking in information from the senses which has not yet come into full awareness) and scheduling requires top down processing (driven by cognition), which is stepwise and requires thoughtful analysis to complete the processing.  

The Buser and Peter (2012) study, which examined gender differences in multitasking, found that both genders (males and females) do not perform better when multitasking.  It was previously suggested that males, hunters, perform sequentially and therefore cannot multitask effectively while females who are known to be gathers can do many tasks at the same time well.  However, when this suggestion is investigated it was found that females prefer not to multitask and their performance suffers just as much as males.

In summary, scheduling is better than multitasking.  This means it is best to complete one activity at a time, rather than many at once for your performance to be at its best.  ​