Cognitive Bias

Cognitive biases are systematic patterns of deviation from rationality in judgment or decision-making. Part of Laws of UX.

Peak-End Rule

People judge an experience largely based on how they felt at its peak and at its end, rather than the total sum or average of every moment.

• Pay close attention to the most intense points and the final moments of the user journey.
• Identify when your product is most helpful, valuable, or entertaining and design to delight the user.
• People recall negative experiences more vividly than positive ones.

Serial Position Effect

Users have a propensity to best remember the first and last items in a series.

• Placing the least important items in the middle of lists can help, since those are stored less frequently in memory.
• Positioning key actions on the far left and right within navigation can increase memorization.

Von Restorff Effect

Also known as the Isolation Effect — when multiple similar objects are present, the one that differs from the rest is most likely to be remembered.

• Make important information or key actions visually distinctive.
• Use restraint when placing emphasis to avoid elements competing or being mistaken for ads.
• Don’t rely exclusively on color for contrast — consider color vision deficiency and low vision.
• Consider motion sensitivity when using motion to communicate contrast.

Zeigarnik Effect

People remember uncompleted or interrupted tasks better than completed tasks.

• Invite content discovery by providing clear signifiers of additional content.
• Artificial progress toward a goal can increase motivation to complete the task.
• Provide a clear indication of progress to motivate users to complete tasks.