Which layer of the five elements of UX design represents how users interact with the interface?

The Surface layer of the five elements of UX design represents the visual and interactive aspects that users directly engage with when using an interface. This includes elements such as buttons, colors, typography, and layout—all crucial for creating a visually appealing and intuitive experience. At this level, the focus is on the sensory experience and emotional response of the user, as this is where they physically interact with the design.

The Surface is where the design comes to life; it encapsulates how users perceive and interact with each element. It's vital for designers to focus on this layer because it can significantly influence user satisfaction and usability. If the Surface is well-designed, it can lead to a more enjoyable and effective interaction, thereby enhancing the overall user experience.

Understanding that the Surface layer is the culmination of all other layers is key. While the other layers (Skeleton, Structure, and Scope) deal with arranging content, functionality, and the presence of features, the Surface is where all those elements coalesce into a cohesive interface that users actually see and manipulate.