What does the principle of continuity in design ensure?

The principle of continuity in design is focused on providing a seamless and coherent experience for users across different platforms or interfaces. This principle ensures that users can switch between platforms—such as mobile, tablet, or desktop—without losing their progress or having to start over. This continuity is vital for maintaining user satisfaction and engagement, as it allows users to fluidly transition through their tasks and interactions, thereby minimizing frustration.

The concept also emphasizes consistent design elements that are recognizable across platforms, aiding in user recognition and comfort. However, simply having visual uniformity (as suggested by other choices) does not capture the essence of continuity, which is fundamentally about maintaining user journey integrity, including their progress and experience consistency. Therefore, ensuring that users can switch platforms without losing their progress best embodies the principle of continuity in design.