Which property of an indicator helps to suggest its usage to users?

The property of an indicator that effectively suggests its usage to users is affordance. Affordance refers to the perceived and actual properties of an object that determine how it could possibly be used. In the context of indicators, this means that an indicator’s design communicates its functionality clearly to the user. For instance, a button that appears raised may suggest it can be pressed, while a switch that looks like it can be flipped may indicate a toggling function. This intuitive understanding helps users interact with various elements in a seamless manner, enhancing usability.

Color contrast, size scaling, and multimodal feedback are indeed important factors in the overall design and functionality of indicators, but they do not inherently suggest usage in the same way that affordance does. While high color contrast improves visibility, and appropriate size scaling ensures readability and ease of interaction, these aspects do not directly convey the intended action of the indicator. Similarly, multimodal feedback—like using sound or vibration in addition to visual cues—enhances the user experience but does not serve as a primary indicator of how to interact with an element.