Alternating attention is very closely related to divided attention but is very different. As the name suggests, when you are alternate the tension between two things it is known as alternating attention.
The primary difference between alternating and divided attention in the case of divided attention the same amount of attention is split into the number of tasks at hand. In the case of alternating attention, the entire attention is shifted from one to another.
Let’s consider a hypothetical example to understand the difference more clearly.
Suppose you could measure the attention into a percentage, the amount of attention a person has 100% at hand.
Supposing a teacher is in class talking to someone on the phone and if she gives 20% of her attention to children whispering in class, 50% to the voice on the phone and 30% to see the other students are doing their classwork, it is an example of divided attention. But if he gives 100% attention to the voice on the phone and then pauses the talk and shifts the entire attention to an announcement it is called alternating attention. In alternating attention, one task is entirely ignored while the focus is only on the other task and it is the exact opposite of multitasking.