What is the functional purpose of motion design in user experience, and when does it become annoying?

Short answer

Motion clarifies spatial relationships between screens, provides immediate feedback for actions, and directs attention. It becomes annoying when it is slow or excessively showy and interrupts task completion.

Explanation

Excellent UX motion feels natural and does not call attention to itself, such as a card expanding to fill the screen and showing the user where the content came from and where they will return when closing it. Excessive animation that forces users to wait a full second for every list item to appear frustrates them and harms efficiency.

Common mistakes

• Using long, showy animations that delay when users can tap interface buttons.
• Removing motion entirely and using sudden jump cuts, making users lose track of their position in the app.

Follow-up questions

• Compare easing curves (Linear, Ease-In, Ease-Out) with spring physics.

Sources

• Material Design — Understanding Motion Principles