Limited Attention

What is limited attention?

Limited attention means we cannot attend to everything available to us. A person focused on one task can miss information that matters to another.

In economics, this helps explain why choices can differ from models that assume people use all relevant information. It is related to Herbert Simon’s bounded rationality: decisions are made with limited information and cognitive resources.

In Simons and Chabris’s 1999 inattentional-blindness experiment, viewers watched people passing balls and counted passes by one group. In a version of the video, a person in a gorilla suit entered the scene. Some viewers missed this unexpected event while carrying out the counting task. They could track the requested activity without noticing another visible event in the same scene. But visual attention experiments do not establish one explanation for every choice. For product design, the useful question is concrete: what does the user need to notice at this moment? Whether a reminder or a change in presentation helps depends on the task and needs to be tested.

An interface example

Imagine someone booking a room who concentrates on comparing dates and prices. A cancellation deadline appears elsewhere on the page, away from those controls. The design question is whether people notice and understand that deadline before confirming. A usability test could examine this and compare a version that places the deadline beside the confirmation summary. This is a hypothetical application to investigate, not a result established by the ball-passing experiment.

Sources: Simon (1955) on bounded rationality, and Simons and Chabris (1999) on limits of visual attention.