Immediate feedback exposes the underlying cause-and-effect relationships so they are easy to learn. When feedback is delayed, the connection between action and result is diffused. The user can’t be sure if the result happened because of a button click or a menu item they selected. This uncertainty leads to confusion and misunderstandings. The user can’t build their understanding of the system because they can’t be sure of what caused the system to react. Immediate feedback allows the behavior of the UI to become apparent and learning becomes easy. Longer breaks between your action and response makes discovery and learning become harder. If it becomes too long, task flow becomes interrupted and we are more likely to switch to different task and lose momentum. We become uncertain if something is completed successfully and we may view it as two different events. If a system is able to respond under 100ms, people will automatically associate causal relationship. Under half a second, users will identify it as slow. Over half a second, the user becomes annoyed. Rapid incremental reversible operations whose impact on the object of interest is immediately visible.
Contributed by Jason Thong, Xiao Zhang, and Deedee Jiang