In The Design of Everyday Things, Don Norman explores key concepts for understanding user experience design through the way we interact with everyday objects.
According to Norman, the characteristics of good design are discoverability and understanding. Discoverability refers to being able to figure out what actions are possible, so you know where and how these actions can be performed. In other words, they're not so hidden that no one can understand what your product does. Understanding refers to meaning. If you design a product, you'd like users to be able to figure out how it is supposed to be used. You want them to understand what is going on.
For Norman, the Principles of Design are:
Visibility – when functionality is clear and visible, users are more likely to know what to do next.
Feedback – for every action there is a reaction. (In other words, something happens, so you know it's working)
Constraints – the kind and number of interactions at a given time are limited for increased clarity.
Mapping – the relationship between two sets of elements that signals cause and effect. (For example, a control panel or a speedometer)
Consistency – there is a similarity between design interfaces and tasks so the user understands possible actions. (Buttons look like buttons, scroll bars look like scroll bars.)
Affordance – a clue that allows the user to understand relationships: what to do, how an object is used, and what is possible. (Signifiers communicate signals on how to use the design.)
Note: The word affordance was not originally coined by Norman, but comes from James J. Gibson's The Ecological Approach to Visual Perception.
An affordance is something that looks like what it's supposed to to. Some affordances in every day life are:
A handle on a mug so you have a place to hold the "cup" without burning your hand.
A handle on a car door so you know where to open the door.
A button that sticks out in a way that makes you want to push it (and maybe lights up when you do).
Barbed wire so you know to stay out. (This is technically an anti-affordance.)
A doorway that stands out from the rest of a wall so you know you can go through. (A secret door or hidden door is designed to be deliberately misleading.)
A door handle so you know if you should push or pull. (even if it's not always clear 😂)
It's not you. Bad doors are everywhere. Vox gets the scoop on Norman Doors from Don Norman himself. [5:31 min]
A Norman Door is defined as:
1. A door where the design tells you to do the opposite of what you're actually supposed to do.
2. A door that gives the wrong signal and needs a sign to correct it.
Don't take mundane experiences for granted! Keep collecting examples from your day to day life, and start considering some of the different ways to improve the design.