Introduction: Design Principles

Design principles are value statements that frame design decisions and support consistency in decision-making across teams working on the same product or service. These principles are fundamental pieces of advice for you to make easy-to-use, pleasurable designs. You apply them when you select, create, and organize elements and features in your work.​

Making decisions is what designers do regularly when designing products and services. Some decisions are straightforward (e.g., where to place the login button), but others require choosing between two competing goals. For example, should we go for a clean, minimalistic design or make content super discoverable? Which user group should we prioritize: power or casual users?

When faced with tradeoffs like these, designers must choose which goal to sacrifice in favor of another. Doing so can be tricky: the choice can feel subjective or random and result in lengthy — and possibly unneeded — debates within large design teams.

Product Design Principles

Product-specific design principles are a helpful device to guide designers to make the right tradeoff decisions. These principles support consistency in making decisions across teams, building confidence, and eliminating fruitless debates.

It’s worth stating that product design principles differ from good design principles, such as usability guidelines, heuristics, or visual design principles. Design principles are specific to the product or service that is being designed.

They represent the accumulated wisdom of researchers and practitioners in design and related fields. Applying them lets you predict how users will likely react to your design.

The Robustness Principle: Be conservative in what you send; be liberal in what you accept.

The Pareto Principle: 80% of the effects come from 20% of the causes.

The Principle of Least Surprise: When two elements of an interface conflict or are ambiguous, the behavior should be that which will least surprise the user.

The DRY Principle: Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

KISS Principle: An example of a principle where you design for non-experts, minimizing any confusion your users may experience.

In user experience (UX) design, minimizing users’ cognitive loads and decision-making time is vital. The authors of Universal Principles of Design state that design principles should help designers find ways to improve usability, influence perception, increase appeal, teach users, and make effective design decisions in projects.

For design principles to be effective, they should:

• Take a stand on which value is important: Each principle should be clear on what value it advocates and why. If the principle is ambiguous about its recommendations, it could be interpreted differently. It can be helpful if a value is explicitly called out over another regularly conflicting value to make the desired choice more obvious.
• Inspire empathy: A design principle should mention why that value is essential to users. Doing so helps designers keep users at the heart of their design decisions.
• Be concise: Design principles are not meant to be an essay. Keep it short and to the point to ensure they’re easily understood, referenced, and remembered.
• Be memorable: If you have content specialists in your organization, it’s worth getting their input in drafting principles to make them memorable (as well as concise). Additionally, you shouldn’t have too many. For example, having 10 or more leads to many being forgotten; reading and understanding them again each time they are needed consumes too much time.
• Not conflict with one another: Each principle should be dedicated to one value only. However, be careful that your principles don’t conflict. For example, if there were a principle about consistency and another about adaptability, then it would not be easy to understand how these values should be prioritized against one another.

You need a firm grasp of users’ problems and a good eye for how users will accept your solutions to apply design principles effectively.

For instance, you don’t automatically use a 3:1 header-to-text weight ratio to abide by the principle of good hierarchy. That ratio is a standard rule. Instead, a guideline you might use to implement a good hierarchy is “text should be easy to read.”

You should use discretion when applying design principles to anticipate users’ needs – e.g., you judge how to guide the user’s eye using symmetry or asymmetry. Consequently, you adapt the principles to each case and build a solid experience as you address users’ needs over time.

Designers use visibility, find-ability, and learnability principles to address basic human behaviors. We use some design principles to guide actions. Perceived affordances such as buttons are an example. That way, we put users in control of seamless experiences.

In her presentation at An Event Apart in Boston, MA, in 2011, Whitney Hess talked about a universal set of design principles for creating great user experiences.

• User experience is the establishment of philosophy for how to treat people. Design principles can outline this philosophy.
• Visual design is a philosophy about how to create an impact. Visual design principles are the foundation for how to achieve that impact. Principles like contrast, proportion, variety, balance, repetition, movement, texture, harmony, and unity form the basis by which we can discuss and evaluate a visual design.
• Why design principles? Consistency of decision-making, shared vision creation, and objective design evaluation.
• Good design does not equal good experience. We create designs that are meant to be used over time. The quality of experience needs to be measured over prolonged usage. Design principles can help us stay on track.

Universal user experience principles

• Stay out of people’s way. When someone is trying to get something done, don’t put up obstacles. Your designs should have clearly defined paths that people can traverse effortlessly.
• Create a hierarchy that matches people’s needs. Variations in font sizes can order content appropriately. Order of use can be used to layout actions by importance. How are people approaching the page? What matters most to them? Give the most crucial elements the most prominence. Prioritize scenarios that get used.
• Limit distractions. A practical design allows people to focus on the task without diverting their attention to other tasks. Aim for linear flows that keep people going.
• Provide vital information scent. Give people a sense of what’s inside/within through strong visual and text cues.
• Provide signposts and cues. Allow people to see where they are in the experience to give them confidence. Give them a sense of where they have been and where they can go.
• Provide context. Communicate how everything inter-relates. Ensure your design is self-contained so people don’t have to jump around to understand what they are looking at.
• Use constraints appropriately. Preventing errors is a lot better than recovering from them. Proactively indicate what is and isn’t possible. Make sure the constraints are worthwhile –don’t be overly limiting to support the structure back-end systems need.
• Make actions reversible. Allow people to undo things to help them recover from errors. There’s no such thing as a perfect design. Nothing can prevent all errors. So, allow people to fix mistakes quickly.
• Provide feedback. Tell people that you heard them. Offer the next step along the path. Design is a conversation, not a monologue.
• Make an excellent first impression. Designing a digital product is a set of rules for managing a relationship.

Your principles

• Are universal principles enough? Every product has its own goals. So, you might need to create your own to guide you toward the right experience for your service.
• Companies like Google, Facebook, Microsoft, and others have their design principles. Without principles, we don’t know what we are trying to achieve.
• Creating your principles: research what’s out there, gather and list out your business goals and brand, brainstorm, narrow down to no more than 10, preferably 7, and make sure they don’t overlap.
• When to use your design principles: kick-off meetings, prioritizing features, critiques, stakeholder presentations, resolving conflicts, post-mortems, and web metrics analysis.
• Help people make their lives better.

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