Universal Principles of Design, Updated and Expanded Third Edition

135 Performance Load

The greater the effort required to complete a task, the less likely the task will be completed.

Performance load is the degree of mental and physical effort required to achieve a goal. If the performance load is high, the probability of successfully accomplishing a goal decreases. If the performance load is low, the probability of successfully accomplishing a goal increases.1

Performance load is the sum of two types of loads:

1. Cognitive load — The mental effort (i.e., attention, perception, memory, problem solving) required to accomplish a goal (e.g., recalling a new phone number). Cognitive load can be reduced by eliminating unnecessary information from displays, chunking information that is to be remembered, providing ...