Performing Simultaneous Tasks
So what happens when we try to perform competing tasks? What happens
when our attention is divided? Preece (1994:105) distinguishes between
primary and secondary tasks. Primary tasks are those tasks which are most
important at that particular time. In order to successfully multitask, Preece
maintains that we need to be able to switch rapidly between the various
tasks. The task currently being carried out is said to be
foregrounded
while
the other tasks are temporarily
suspended
.
In principle at least, this appears to be a more than adequate solution to
the problem of multitasking. There are, however, a number of problems as-
sociated with multitasking and which detract from the apparent benefits of
performing multiple tasks at the same time. The first problem is that people
are very prone to distraction (
ibid.
). When switching between tasks, our at-
tention is temporarily not focussed, leaving our attention prone to becom-
ing focussed by other stimuli. Also, there is a tendency to forget where we
left off when we return to a task with the result that we can return to a task
at a different point from where we left it. Another problem associated with
switching tasks is that the more intensely we are concentrating on a task,
the more difficult it will be to switch our locus of attention to a new task
(Raskin 2000:20).
Raskin (2000:21) also states that when we attempt to perform two tasks
simultaneously, our performance on each task degrades. This phenomenon
is known as interference and can be explained by the fact that both tasks are
essentially competing for the same finite amount of processing capacity. An
important point to bear in mind here is that Raskin is referring to two tasks
which are not automatic and as such require large amounts of processing
capacity. But what are automatic tasks and how do tasks become automatic?
To understand this we will need to examine the cognitive processes in-
volved in learning.
129
Understanding Users
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