Providing User Feedback
Feedback helps people know what an app is doing, discover what they can do next, and understand the results of actions.
Unobtrusively integrate status and other types of feedback into your interface. Ideally, users can get important information without taking action or being interrupted. Mail, for example, displays status information in an Activity panel that can be displayed if the user wants to see it. This panel doesn’t interfere with the user’s actions, but can be checked at any time with a quick glance.
Avoid unnecessary alerts. Alerts are inherently disruptive by design and should be used sparingly to avoid making the user experience less pleasant. Only use alerts to deliver important—and ideally actionable—information. For additional guidance, see Alerts.
Warn people when they initiate a task that can cause an unexpected and irreversible loss of data. Such warnings are important, but like other alerts, they lose their impact if they appear too often. Don’t warn users when data loss is expected. For example, the Finder doesn’t warn the user every time they throw away a file because moving a file to the trash is an intentional action. Similarly, if a command can’t be carried out, people want to know why and what they can do instead.
Consider providing haptic feedback through the user’s trackpad. A Force Touch trackpad can use haptics to enhance the user’s perception of certain actions and results. See Haptic Feedback.