Cause and effect design

Actions in Apple's interfaces have clear, logical outcomes. When you tap Edit in Notes, related tools appear and text becomes selectable. In WhatsApp, as shown above, when you start typing, the interface shows "online" and indicates you're "typing..." to your chat partner, creating clear feedback about user activity.

Each action triggers a coherent chain of interface changes. System changes show clear relationships. Switching to Silent Mode changes relevant indicators and enables Do Not Disturb updates across devices. These connected responses help users understand how different parts of the system work together.

Every state change should make sense to users. If an app needs location access, the request appears when location features are used. If storage is full, warnings appear when trying to download. These logical connections help users understand why things happen and how to address them.