The Grand Unifying Theory of Design
Design isn’t just about how something looks. It’s a universal problem-solving process that can be applied to any discipline to create valuable and delightful experiences.
“In most people’s vocabularies, design means veneer. It’s interior decorating. It’s the fabric of the curtains of the sofa. But to me, nothing could be further from the meaning of design. Design is the fundamental soul of a human-made creation that ends up expressing itself in successive outer layers of the product or service.” — Steve Jobs
Design is creating something that effectively solves a problem in a specific situation.
That’s not how most think of design though. People generally associate it with visual aesthetics or how something looks. For some there’s an aura of mysticism around it, as if it's an elusive art form that only a few can master. This narrow view of design misses how universal the core principles are.
There are a lot of design sub-disciplines. But if you think about big picture “Design”, it’s really about making it so something solves a problem well. In this way, design encompasses basically anything you do that provides value to others. A well-designed experience solves a problem and makes people feel delighted in the process.
Everything you do can benefit from understanding the fundamentals of design.
Making something look good can be important, but it’s usually the last step. The first step is understanding the actual problem you’re trying to solve.
Design: from the top down
Design is fitting form to context
The first thing to understand is that all design is relative to the context it’s used in.
The goal of all design is “goodness of fit”: how well the form (the artifact or thing you’re designing) fits in the context (problem or situation it’s being used in). The real object of discussion is not the form alone, but the unity of both form and context.
In his book “Notes on the Synthesis of Form,” Christopher Alexander gives an example of designing a tea kettle:
Let us consider an ensemble consisting of the kettle plus everything about the world outside the kettle which is relevant to the use and manufacture of household utensils. There's a clear boundary between the kettle because it happens to be a physical object. But one could easily make changes in the boundary — implying that the kettle is the wrong way to heat domestic water to begin with. It can quickly be expanded to include the entire house, claiming that it is not the kettle but the method of heating kettles that needs to be redesigned. In this case the kettle becomes part of the context, while the stove perhaps is form.
Boundaries between the form and the context are fuzzy and movable. Anything in the world that makes demands of the form is context. Boundaries also overlap. A sink exists in the scope of a bathroom, overlaps with the context of a shower, which is in a house, which is in a community. You design a sink to fit with what’s needed in a bathroom, but also in someone’s life. You need to understand what level of abstraction you’re designing for.
How do you define good fitness? This is one of the things that makes design hard.
The only surefire way is exposing the design to the real world and observing how well it solves the problem. Or through experimental trial and error during the design process (see my essay Take the Iterative Path on why this is needed).
Sometimes trial and error isn’t possible or is too costly. Once you build a house it’s too late to know if it’s designed properly! And even then, how well it fits its occupant’s needs may only be known after many years of use.
For this reason, good fit is generally expressed through minimizing misfit. Misfit between form and context is much easier to spot. Like a kitchen that’s hard to clean, rainwater leaking into the building, or a button that no one understands the purpose of. Avoid misfit (bad design) and you’re well on your way to making it good.
All mediums are defined by their constraints: from art to comics, novels, films, and shows. In “Understanding Comics”, Scott McCloud explains how storytelling is just translating a story to our senses through their chosen medium. The storyteller’s job is to manage and work around their constraints.
Design is no different. Most of the practice of design is managing trade-offs from constraints.
Constraints of context. Where are your boundaries? What are the factors imposed by the context?
Take the tea kettle example from above. There are lots of different factors for the form (ease of holding, retaining heat, etc.). But you’re already drawing a boundary around a specific device for solving the problem. What other method can you use to get hot water? What if hot water came from the tap? More on this in the next section.
Constraints of form: What interfaces are possible? What’s required of them?
Is a complicated user interface good, or bad design? It depends on the context and the nature of the interface. Take Microsoft Excel. Anyone exposed to it for the first time would have a very hard time figuring out how to do much. But that’s fine! Excel is mostly for power users. The functionality and learning curve are important parts of the product.
Excel is also designed specifically for use on a laptop or desktop computer. This gives it specific constraints. You can’t just port the same product to a mobile device because the constraints (and context) are different.
Constraints of reality: What is possible to make? How is it going to be made? (You might think this doesn’t need to be said. Many engineers I know would beg to differ.)
The best designers know exactly how their design is built, and the trade-offs inherent in the process of creating it. To paraphrase Warren Buffett: “I’m a better designer because I’m a maker, and a better maker because I’m a designer.”
Constraints of resources: What do you have to solve the problem? The reality is that the resources you have determine what can be done.
Financial and human resources — how much money and people do you have?
Time — how much time do you have? How do you know when it’s good enough?
Design tools — what tools do you have to assist the design process? (Designing a building using sophisticated CAD tools can have radically different constraints than pencil and paper.)
The key to good design is managing all the trade-offs imposed by these constraints. And there can be a lot of them. In a real-world design problem, it’s not possible to solve for every variable. You’ll have to balance and prioritize the tradeoffs, which will mean compromising on some and finding innovative solutions to others.
Finding the boundaries of context
“Design begins by asking, who is this for and what do they need from it? A good architect, for example, does not begin by creating a design that he then imposes on the users, but by studying the intended users and figuring out what they need.” — Paul Graham
How do we define context and what the design boundaries are? What method do we want to use to solve the problem?
This is where jobs-to-be-done theory comes in. There are entire books written on this so I’ll try to be brief.
When you use a product or service, you’re “hiring” it to do a job for you. A “job” is the progress that a person is trying to make in a particular context. There is a gap in what they want vs. what exists, and the job fills it.
A job can only be defined relative to the specific context in which it arises. In other words, a job is the ensemble of form + context. It can be phrased in the statement:
“When I’m [context], I want to [motivation], so I can [outcome].”
There are many methods that can be hired to do the job. If the problem exists, people are likely already hiring something to make progress on it. The job people are hiring something for may not be obvious, and it can take a lot of work to figure it out.
Continuing our tea kettle example — if the outcome is having hot water, this could be done by multiple methods like heating a kettle over the stove, getting it directly from the faucet, or maybe using a microwave. Methods may not seem to be related at all, like:
The job of having a business meeting can be filled by an airplane or by Zoom.
The job of entertaining oneself can be filled by watching TV, playing video games, reading a book, or going for a hike.
These examples are higher-level, less specific jobs. A well-defined job is multilayered and complex. It has needs that are:
Emotional — how it makes them feel.
Social — how they believe they’re perceived by others while using it.
Functional — the practical and objective requirements.
When you know the job, you can choose what method that’s best to do it. (Or you may be constrained to a specific method to solve the problem.)
Once a method is determined, you can design the interface.
An interface is the medium a person interacts with.
The goal of interface design is to match the conceptual model (how it works) with the user's mental models (how they think it works). The designer needs to communicate to users, but can only via the user interface.
“A good conceptual model allows us to predict the effects of our actions.” — Don Norman
A conceptual model is the actual model of how it works given to the person through the interface. If the interface doesn’t make the conceptual model clear and consistent, it won’t match with the user’s mental model and problems will ensue. This is “bad” design — in other words, a misfit between form and context.
If you make a tea kettle that doesn’t have a handle, its user — confused, no doubt — will grab it whatever way they can, possibly spilling water or burning themselves. Misfit!
“Interfaces, as Geoffrey James has said, should follow the principle of least astonishment. A button that looks like it will make a machine stop should make it stop, not speed up.” — Paul Graham
How do we make a well-fitting user interface? Ultimately we only know by observing how it’s actually used.
But there are some basic principles of interaction we can use. Don Norman defines some of these attributes:
Affordances — “The perceived or actual properties of a design that suggest how it can be interacted with.” In other words, what does a design allow for? A handle affords to be gripped. A button affords to be pressed. A ball affords to be rolled. A door with a flat surface affords to be pushed. (Even though sometimes in needs to be pulled. Misfit!) A product affords to be hired for a job-to-be-done. (Even if the job wasn’t intended by its product’s creator.)
Signifiers — Any visual mark, sound, or perceivable cue that indicates the appropriate behavior. If affordances define what actions are possible, signifiers specify how people discover those possibilities, and how the actions should take place. Labels, diagrams, arrows, audio alerts.
Mappings — The relationship between controls and their effects, such as the spatial or functional relationships between buttons and the actions they trigger. The classic example here is the knobs that turn on a stove. How do you know which knob controls which stove?
Feedback — The information provided to the user that indicates the results of their action. Not receiving continuous feedback about the results of actions can result in misfit between intention and outcome. Systems are more usable when they clearly indicate their status, the possible actions that can be performed, and the results of those actions.
How do we effectively apply these principles?
This is where patterns come in.
A pattern language
Designers communicate to users using a language of patterns, which are functional solutions to problems that exist at every level of abstraction.
Every design is composed of patterns. Each pattern addresses one or more needs of the design as a whole. A button on a machine or in software allows a person to initiate an action.
There are commonly used patterns in all design disciplines. Here are a few examples from different areas:
Software UI patterns — Buttons, type layouts, tabs, checkboxes, more complex patterns like wizards, drag and drop, or complex tables with filters. Design frameworks like Bootstrap provide a collection of tried and tested patterns that are known to work well in specific contexts.
Architecture patterns — Doors, entries, kitchen layouts, stairs, moulding, windows. Read "A Pattern Language" for much, much more. Corridors (hallways) seem obvious but the pattern needed to be invented.
Book patterns — Headings, chapters, lists, table of contents, index, paragraphs, elements of typography.
Film grammar — Every medium uses its own composable grammar that’s analogous patterns. In film, you have grammar like: Wide shot, closeup, slow-motion, zoom, split screen, jump cut, flashback.
Food patterns — All prepared food is designed. Even the non-manufactured "natural" kind. There are patterns in flavor, texture, visual appeal, and how they’re all combined.1
Patterns don’t have to be universal — they can be unique to a small niche or even a single design. Common patterns can help though because if people are familiar with them the interface will match their mental model better.
I think about it through the lens of natural selection. In the global evolution of design, patterns are the unit of selection, similar to genes in biological evolution or memes in cultural evolution. Patterns that successfully solve a problem in a specific context are reused and “survive” over time to become core parts of a global design language. Like buttons in software, hallways in architecture, salt in food, chapter headings in books, and a closeup shot in film. A design combines many patterns and the more effective it is at doing its job at an efficient cost, the more “fit” it is.
It's important to note that just because a pattern is in common use or generally solves a certain problem, doesn't mean it's right for a particular design.* Every design uses its own pattern language. The language for a particular design becomes a sort of code that helps the designer achieve fitness more effectively.2
Patterns occur at every scale. The flow of navigation in a software app down to the look of a button. The layout of rooms in a home down to the decorative flourishes on a moulding. Whether or not it’s conscious, design patterns are inevitably chosen at all levels of abstraction. And once again, depending on the context of the situation, different scales can matter more than others.
For some designs, visual appearance is key to its usability.
The visceral level
“People DO judge a book by its cover.” — Mike Markkula (original investor in Apple)
Finally we come to visual design.
Don Norman calls this the “visceral” level: the automatic, pre-wired, gut-feeling you get from experiencing a design with your senses. Visceral design is all about immediate emotional impact. It has to feel good and look good.
The Aesthetic-Usability Effect is a phenomenon in which people perceive more aesthetic designs as easier to use than less aesthetic designs (whether they are or not). Designs that make you feel good are easier to deal with and produce more harmonious results. Think Apple products, sports cars, Slack vs. Microsoft Teams, or a book with good typesetting.
Making something look good can be a big part of usability. When you wash and polish your car, doesn’t it seem to drive better?
Much of this effect is due to our evolutionary programming. Positive affect comes from things throughout history that have offered food, warmth, or protection: warm, comfortably lit places; sweet tastes and smells; highly saturated hues; soothing sounds and rhythms; smiling faces; symmetrical objects; rounded, smooth objects. Negative affect comes from things like: heights; unexpected loud sounds or bright lights; darkness; empty, flat terrain; crowds of people; rotting/decaying smells; bitter tastes; sharp objects.
As always, it depends on the context. No design is inherently good or bad — only compared to the needs of the people who use it.
Which is designed better, the hibiscus flower or the blobfish? Neither! Both have evolved to be perfectly suited to their context. If the blobfish was “prettier” to humans, it would likely be killed, and thus poorly-designed for its environment.
These are the homepages of two large conglomerates: Berkshire Hathaway and Alphabet. At the visceral level, the Alphabet page is clearly better. Lots of white space, pleasant fonts, simple colors. But who are the primary users of these sites? What is the job they need done? For Berkshire, users are mostly looking for the link to Warren Buffett’s latest letter, or their annual report. Berkshire provides every potential action right up front, compatible with every browser and format. The aesthetics in this case are also part of the company’s frugal brand.
In any design discipline, the pattern language includes visual patterns. Some have survived a long time, and thus more objective: serif fonts, proximity, negative space, symmetry, etc.
A lot of visual design comes down to a subjective sense of “does this feel good”. Or in the words of Christopher Alexander, does it make you “feel alive”?
Final quiz: Which street makes you feel more “alive”? What are the patterns in each that contribute to positive or negative emotion? What about good or poor fit with needs?
Design is a meta skill
If you’ve made it to this point, it should be clear: all design depends on the context it needs to fit with. The job of a designer is to discover these constraints and how they translate into the requirements of the design. Using good patterns can help create experiences that both match our needs and make us feel good in the process.
If you can internalize the above principles, design is a meta skill that can be used anywhere to help you solve problems, create better experiences, and make people happier.
Although the fundamentals of design will always be the same, the tools that assist it continue to change. With AI, a new renaissance of generative design is currently underway. These tools will give us enormous capabilities — and make the fundamentals even more relevant.
I’ll close with this passage from Don Norman:
“We are all designers. We manipulate the environment to better serve our needs. We select what items to own, which to have around us. We build, buy, arrange, and restructure: all this is a form of design. Through our designs, we transform houses into homes, spaces into places, things into belongings. The best kind of design isn’t necessarily an object, a space, or a structure: it’s a process—dynamic and adaptable.”
For a much better and deeper look at design principles, these are the books I’d recommend:
“The Design of Everyday Things”, Don Norman
“Emotional Design”, Don Norman
“Notes on the Synthesis of Form”, Christopher Alexander
“The Timeless Way of Building”, Christopher Alexander
“A Pattern Language”, Christopher Alexander
“Competing Against Luck,” Clayton Christensen
Thank you to Celeste for reviewing drafts of this, and Ryan Singer for inspiring some of the concepts.
Working for the candy company Mars, Bob Moesta helped revitalize the Snickers brand after realizing the job-to-be-done for many Snickers consumers was that they are just hungry, and needed an easy-to-consume energy boost. This led to them changing the formulation for the bar so that it was more “food like” and feels more satiating, culminating in the “you’re not you when you’re hungry” marketing campaign.
With design patterns, it’s usually best not to reinvent the wheel. Commonly used patterns are common because they work. What happens when they don’t? What does design from first principles look like? Some thoughts for a future essay. . .