An interface can be visually sparse and still ask a great deal of someone. Comparing prices across separate pages, remembering a code, and translating unfamiliar labels all require mental work. Cognitive load concerns that demand, including how the task and its presentation interact with a person’s knowledge and circumstances.

The concept comes from research on learning and working memory, but product teams often use it more broadly to discuss mental effort. That broader use should remain specific enough to identify what is making an experience difficult.

Look for the work the interface leaves to memory

If a person must remember the details of three plans while opening each in a separate view, the comparison depends on memory as well as judgement. Putting relevant differences together may help, even though it adds information to the screen.

Nielsen Norman Group’s recognition and recall guidance explains why visible options and information can reduce the need to retrieve them from memory. This does not mean displaying every possible detail at once. The question is which information the current decision requires and where it can be found when needed.

In an illustrative expense form, a persistent summary of the amount and currency may be more useful than another decorative simplification. It removes the need to revisit an earlier step to check a fact.

Distinguish task complexity from avoidable difficulty

Some decisions are inherently demanding. Choosing insurance, configuring permissions, or reviewing a contract may require careful thought. Removing necessary explanation can make the screen shorter while making the decision harder or less informed.

Investigate unfamiliar terminology, poorly grouped information, interruptions, and uncertain consequences. A person’s mental model affects how they interpret the same screen: an expert may recognise a useful shortcut where a newcomer sees an unexplained code.

Use task analysis to understand the sequence and dependencies, then test changes that address a particular source of effort. Avoid assuming that the fewest clicks or the fewest words will produce the best experience.

Gather evidence rather than diagnosing from appearance

During usability research, observe revisits, lost place, repeated comparisons, errors, and requests for clarification. Ask what participants were trying to work out. These behaviours can suggest difficulty, but none is a direct reading of cognitive load by itself.

Pair observations with suitable self-report or performance measures when the decision needs measurement, and account for familiarity and task differences. A slower participant may be making a careful decision rather than struggling. The useful finding explains the unnecessary work the design creates and how the proposed change makes that work easier to manage.