Discoverability
Discoverability refers to how easy it is to determine possible actions, and how to complete those actions when a system or object is unfamiliar. Think about objects you have interacted with for the first time like a coffee maker in a hotel room. Did you know how to use it by looking at it for the first time or did you struggle? Often, people blame themselves when they don’t immediately understand how to use something, but it’s not their fault. If it’s a common object like a phone or coffee maker, it should be intuitive to use, even if it’s the first time. The way to achieve this is to make the actions of the system discoverable.
Discoverability is not a single principle all on its own because depends on several design principles working together: affordances, signifiers, mapping, and conceptual models. Affordances are the relationship between the properties of an something and the ability for the user to determine how to use it. Often, affordances have signifiers that demonstrate how to use it, thus giving the object affordance. Mapping helps the user understand the relationship between different elements, and conceptual models display how a system works. Having a conceptual model of how the system works and being able to see how the various elements connect to each other help the user understand the system and how to operate it. When all of these elements are working properly, the user is able to discover what to do to achieve their goal. It just feels easy and intuitive to use without a lot of effort or understanding.
Example from the readings

Examples from the Web
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Example from the World

Works Cited
[1]Norman, D., & Tognazzini, B. (2015). How Apple is giving design a bad name. Retrieved from: https://www.fastcompany.com/3053406/how-apple-is-giving-design-a-bad-name