You’ve probably been there. You’re at a fancy hotel or a modern office building, and you walk toward a door with a sleek, vertical metal handle. You pull. Nothing happens. You pull harder, thinking maybe it’s just heavy. Still nothing. Then, you notice the tiny "PUSH" sign. You feel like an idiot, right? Don Norman wants you to know it isn’t your fault. It’s the door’s fault.
This concept of "user error" being a failure of design is the heartbeat of Don Norman Design of Everyday Things. Originally published in 1988 as The Psychology of Everyday Things, the book shifted the entire landscape of how we interact with the world. Norman, a cognitive scientist who later became a VP at Apple, realized that if a person can't figure out how to use a toaster or a light switch, the designer failed. Period. It's a radical idea that still feels fresh because, honestly, we are still surrounded by terrible gadgets that make us feel dumb.
The Norman Door and Why You Can’t Open It
The most famous example from the book—and now a staple in design schools everywhere—is the "Norman Door." It’s basically any door that gives you the wrong signal. If it has a handle, your brain says "pull." If it has a flat plate, your brain says "push." When a designer puts a pull-handle on a door that only pushes, they’ve created a trap.
Design is communication.
When you look at an object, it should whisper its purpose to you without a manual. Norman breaks this down into a few core principles that seem simple but are actually incredibly hard to get right. First, there's affordance. This is a fancy word for what an object allows you to do. A chair affords sitting. A button affords pushing. If the affordance doesn't match the function, you've got a problem.
Then you have signifiers. These are the clues. A handle is a signifier. A cursor changing to a hand icon on a website is a signifier. Without these, we’re just guessing. Think about those modern kitchen stoves with touch-sensitive glass tops. No knobs. No tactile feedback. You're sliding your finger around hoping the heat turns on. That is a failure of signifiers. It's sleek, sure, but it's a nightmare to use when your hands are wet or you're in a rush.
Mental Models: Why Your Brain Struggles with Smart Homes
Ever tried to use someone else’s shower? You stand there naked and shivering, staring at a single chrome lever. Does left mean hot? Do you pull it out or turn it? This is a clash of mental models.
A mental model is the internal map you have of how things work. You have a mental model for a car, a smartphone, and a book. When you encounter something that doesn't fit your map, frustration sets in. In Don Norman Design of Everyday Things, Norman explains that designers often have a "design model" that is totally different from the user's "user model." The only way those two connect is through the "system image"—the physical object itself.
The Gap of Execution and Evaluation
Norman describes two big hurdles we face when using stuff:
- The Gulf of Execution: This is the distance between what you want to do and how you actually do it. If I want to save a file but can't find the 'save' button, that's a wide gulf.
- The Gulf of Evaluation: This is about feedback. I clicked the button—did it work? If the computer just sits there with a frozen screen, I'm stuck in the gulf of evaluation.
Good design closes these gaps. It gives you a clear path to action and immediate, understandable feedback.
Think about the "Save" icon. Most people under thirty have never used a physical floppy disk, yet the 3.5-inch diskette remains the universal sign for saving data. It's a legacy signifier. It works because the mental model has been passed down, even though the physical object is extinct. But move that icon or change it to something "minimalist" like a random dot, and suddenly the Gulf of Execution becomes a canyon.
Mistakes Happen (And Designers Should Expect Them)
One of the most human parts of Norman's philosophy is his take on error. He categorizes them into slips and mistakes. A slip is when you intend to do one thing but do another—like putting the milk in the cupboard and the cereal in the fridge. You knew the right way, you just zoned out. A mistake is when you have the wrong goal entirely because you misunderstood the system.
Most products punish you for these. Norman argues they should embrace them.
📖 Related: Why the satellite Haiti Dominican Republic border image is actually a warning
The concept of constraints is vital here. Physical constraints make it impossible to do the wrong thing. Think about a USB-C cable versus the old USB-A. With the old one, you had a 50/50 shot of getting it right, but somehow it always took three tries. It didn't have the right constraints. USB-C is reversible. It doesn't matter how you plug it in. That is a design that respects human fallibility.
The Evolution to Emotional Design
It’s worth noting that Norman’s views changed over time. In the original version of Don Norman Design of Everyday Things, he was very focused on utility and logic. It was all about "does it work?" and "is it clear?"
But later, he realized that humans aren't just logic machines. We're emotional. He eventually wrote Emotional Design, admitting that attractive things actually work better. Why? Because when we use something beautiful, we feel good. When we feel good, we’re more relaxed. When we’re relaxed, our brains are more flexible and better at solving minor problems. If you love the way your teapot looks, you might not mind as much if it drips a little bit.
This creates a tension in modern tech. We want things to be "clean" and "minimal," but minimalism often strips away the signifiers we need to actually use the device. Look at modern car interiors. Tesla and other manufacturers are moving everything—windshield wipers, glove box releases, side mirror adjustments—into a central touchscreen. From a cognitive load perspective, this is a disaster. You have to take your eyes off the road to navigate a menu for a physical task. Norman’s principles suggest that critical tasks should have physical, tactile affordances.
How to Apply These Lessons Today
If you're a creator, a business owner, or just someone tired of fighting with your printer, there are real, actionable takeaways from Norman's work. It isn't just for "designers" in the traditional sense. It's for anyone who builds anything for other people to use.
Map your functions to reality.
If you have a row of four lights and a row of four switches, the switches should be in the same layout as the lights. If they are in a straight line but the lights are in a square, people will always flip the wrong one. This is called natural mapping. Use it everywhere.
Provide immediate feedback.
Never let a user wonder if their action "took." Whether it’s a haptic buzz on a phone, a click sound, or a visual change, feedback is the only way we know we’re in control. Silence is the enemy of good design.
The "Five Whys" of Error.
When someone uses your product or service and fails, don't ask "What's wrong with them?" Ask "Why did they do that?" Then ask why four more times. Usually, the root cause is a confusing signifier or a mismatched mental model.
Standardize or Innovate—Don’t do both half-way.
Standards are great because they outsource the mental model. We know red means stop. We know a gear icon means settings. If you’re going to break a standard, your new way better be significantly more intuitive, or you’re just creating friction for the sake of ego.
Design is often treated as "making things look pretty." But after reading Don Norman Design of Everyday Things, you realize it's actually an act of empathy. It's about taking the time to understand how another person thinks, what they fear, and how they move through the world. It’s about making the world a little less frustrating, one door handle at a time.
Practical Next Steps for Better Design
- Audit your environment: Walk through your office or home and find one "Norman Door"—an object that consistently confuses you or guests.
- Observe a "Naive User": Watch someone try to use your website or product for the first time without giving them any hints. Don't speak. Just watch where they click and where they hesitate.
- Simplify the Gulfs: Look at your most important task (like a checkout process or a sign-up form). Identify if there is a clear signifier for the next step and immediate feedback once it's completed.
- Read the updated version: Norman revised the book in 2013 to include digital interfaces and modern technology. If you only read the 1988 version, you're missing his thoughts on the "screen-based" world we live in now.