When thinking about designing in terms of products and environments, in other words outside of a purely artistic context, what results in something that is “well-designed”?

In 2006, my co-founder Joel Spolsky wrote about famed automobile designer Tom Gale's assessment of good design, namely that it “adds value faster than it costs”. In the context of product development, Joel noted, “design is something you only have to pay for once for your product. It’s a part of the fixed costs in the equation, not the variable costs. But it adds value to every unit sold.”

But in addition to enabling things to be sold at a better margin, good design also helps in other ways, including by minimizing entropy, helping users direct their energy towards goals more efficiently than alternative designs (or a lack of design entirely). In an era in which "vibe-coded" software is taking off, and barriers are lowering for creating new informational tools that do as users ask, but not necessarily in a good or intelligent way... this matters more than ever.

Aspects of Good Usable Designs

There are many lists that purport to outline “rules of good design”.

Legendary designer Dieter Rams (one of Jony Ive's foremost inspirations) asserted that good product design could be characterized by ten traits:

1. Good design is innovative
2. Good design makes a product useful
3. Good design is aesthetic
4. Good design makes a product understandable
5. Good design is unobtrusive
6. Good design is honest
7. Good design is long-lasting
8. Good design is thorough down to the last detail
9. Good design is environmentally-friendly
10. Good design is as little design as possible

Jakob Nielsen outlined his own list of ten heuristics for good usable interface design, in 1994. Such designs should, he said (although I paraphrase):

1. keep users informed about what is going on, through appropriate feedback within a reasonable amount of time
2. speak users' language: using words, phrases and concepts familiar to them rather than internal jargon (leaky abstractions) or overly-technical language
3. provide users with control: escape hatches, emergency exits and the ability to reverse course
4. be consistent and standardized: users should not have to worry that words, situations or actions may mean different things
5. prevent error states from occurring in the first place, and check users' intent when engaging in error-prone actions
6. minimize demands on user memory by making options visible, retaining previous context, and importing relevant settings where applicable
7. support experienced power users by providing accelerative shortcuts, personalization, and customization options
8. not contain irrelevant or rarely required information
9. help users identify, understand, and rectify errors
10. minimize the need for additional explanation (but be accompanied by documentation)

Dozens of other lists from equally prominent designers and architects in their fields posit "rules", "heuristics", and "guidelines" for producing "good designs". Fundamentally I believe these all boil down to three aspects: the functionality contained within a design, its aesthetic appearance, and the symbolism it employs or conveys. This third area is often overlooked, but is inherent to the “intuitiveness” of many designs, as well as their signalling value.

Aesthetics

Good aesthetics attract attention and concentrate users’ energy. Aesthetics can make things easy and pleasurable to engage with.

Aesthetics are sometimes treated as a superficial layer of “styling”, but in practice they often act as interface glue, reducing the mental effort required to parse a thing, and making correct actions feel obvious while deterring improper ones.

In the simplest case, aesthetics help with legibility and hierarchy. Clear typographic structure, spacing, contrast, and alignment allow users to rapidly form a model of “what matters” and “what can be ignored”, without reading everything. In the physical world, material choices and finishes similarly help users infer which surfaces are touchable, durable, washable, fragile, or expensive.

Aesthetics also matter over time. Products that are visually calm, consistent, and proportionate are easier to return to, especially under fatigue or stress. In that sense, aesthetics lower the ongoing energy required to use a tool, and increase its working life.

The trap is mistaking novelty for quality. Aesthetics that are optimized for impressing in screenshots or for short-term fashion can raise entropy: inconsistent components, decorative motion, and dense ornamentation can increase cognitive load and make systems harder to maintain. Good aesthetic design therefore tends to be conservative in the ways that protect comprehension, and expressive only where it adds some kind of durable value.

Symbolism

Symbolism is an important design factor insofar as it helps things be easily recognized, categorized, or ‘bucketed’ by users. Symbolism allows a thing's mechanisms of action to be ‘known’ without having to be guessed. For example, a "play" button and a "stop" button on an audio player, or the green-red/top-bottom position of traffic lights.

A thing itself may also come to carry symbolism: a particular consumer brand may imply some cultural affinity, a particular piece of jewellery a religious belief, or a specific kind of tattoo some gang affiliation.

I consider symbolism to be a design’s ability to communicate without verbal or written instruction or explanation, in reference to either its own purpose and utility: in a digital context often through sight and sound, but in other cases also through smell, taste, and touch; or its context: symbolism in an environment might tell you something about what kind of a place it is (e.g. a burial site) — or an object might reveal something about its owner (e.g. some belief).

Aesthetics can sometimes be a way of expressing symbolism, albeit an imperfect one. For example, a subscriber to nazi ideology may express their aesthetic appreciation for heroic realism, enabling them to deniably signal their beliefs to others. However, a person who is not a nazi may also just like the art style, landing them in an uncomfortable situation. While some correlation may therefore exist between people in possession of such artwork and those who hold nazi beliefs, it may be extremely weak. On the basis that aesthetics may be appreciated independent of their symbolism, I consider them to be distinct aspects of good design.

Symbols are things which are instinctively recognizable, requiring minimal cognitive parsing. The most effective symbols may be understood across cultures, and perhaps even time (e.g. in the case of long-term nuclear waste warning messages).

However, symbolism is not only about recognizability, but also credibility. In signaling theory, costly signals are those that demonstrate believability precisely because they are expensive to produce or sustain, and because cheap imitators cannot easily afford to replicate them. Many “premium” products therefore trade partly on symbolism that is hard to fake without real effort: tight tolerances, low defect rates, robust materials, long warranties, and consistent after-sales support.

In software, product development focused on speed, stability, graceful degradation, thoughtful copy, accessibility, and smart defaults are all user-recognizable symbols of good design. These require careful crafting, QA, and organizational discipline, and can therefore signal competence and seriousness more honestly than superficial ornamentation.

Committing to what your software won't do can also be a form of costly signalling, insofar as it involves constraining one's own addressable market in order to signal hyper-focus on something else.

Functional

Functional design ensures products, systems, or environments serve their intended purpose: satisfying any requirements, while minimizing side-effects or constraints on use, allowing a "function" to be performed with minimal expended energy or input.

For some proponents of functional design (such as Dieter Rams), form follows function — designs should be unobtrusive, exhibiting a neutrality that allow their use across versatile environments — as well as useful, forgoing things which may detract, such as ornamentation.

Tools may be multi-functional, but should still be simple: trivial to understand, and easy to use.

And unless the need for products is a one-time occurrence, products should remain functional for a long time (with Rams' principle of long-lasting durability referring to the avoidance of following fashions, so as not to prematurely shorten a product's lifespan).

In my experience, products with good functional design are easy to identify during their real-life use because they have a habit of positively surprising users (who haven't read a product's documentation) when subjected to new demands, requirements and contexts, revealing useful hidden features, and adapting to circumstances effortlessly.

They achieve this often through deceptive simplicity: appearing to be one thing on the surface, but in fact abstracting great complexity (effectively, without leakage). Well designed products may even do this in an onion-like fashion, with outside layers abstracting inner abstractions. For example, even when taken apart, many Apple products historically retained something of their aesthetic appearance and simplicity: demonstrating “design thinking” even on the inside. Such surprise and effective abstraction generally appear hand-in-hand with attention to detail, and a thorough understanding of a product's users and usage environments.

Surprise is achieved by presupposing user needs, and accounting for eventualities in ways that are not distracting (or even obvious at all) to the user until the moment of requirement. But when the need arises, those products simply “work”.

Similarly, highly functional products may account for their own eventual failure, for example by degrading gracefully, rather than failing catastrophically all at once.

Optimizing Good Design

People argue about which type of design is better. We’re told there are “functional designers” and “pure aesthetes”. Comparatively little attention is paid to the value of symbolic design outside of accessibility affordances, safety-relevant signposting, and visual storytelling (from mysticism to brand identity).

In my view, “good design” is ultimately a trade-off between all three of these things — sitting on the Pareto frontier of them all. This means that it is not possible to make any one aspect of a thing (e.g. its functionality) better, without making any of its others worse (e.g. symbolism, or aesthetics).

Different types of consumers, environmental contexts, and operational requirements may value different positions on the Pareto frontier. For example:

• For some consumers aesthetics take precedence (e.g. an object is primarily ‘displayed’, but not ‘used’, so its functional design comes second to its aesthetic appearance).
• In some environments symbolism is paramount (e.g. under conditions of stress, such as in the military, or when operating aircraft, enabling easy recognition/intuitive understanding of controls may be critical to health and safety). Symbolism, as a signaling tool, is a helpful means of coordination in decentralized settings.
• In other cases functionality is key (e.g. in professional tools that support frequent, time-sensitive, and error-intolerant work — IDEs, CAD tools, kitchen knives, medical devices — where reliability, efficiency, and ergonomics dominate).

Not all users may share a sense of aesthetics. Symbolism may differ across cultures. And functionality may require designs to be combined with other inputs (e.g. physical strength, or a complementary product) to be realized.