User eXperience

Important principles of UI design every designer should know

The modern-day interface should be intuitive, aesthetically superior and helpful to users. Achieving these as a designer is no easy feat.

Good designers follow certain principles of UI design to attain top-tier visuals in their projects with ease.

Is your interface not looking as great as you envisioned? Then maybe it's because you aren't aware of the simple yet powerful rules that underlie most outstanding UI designs. Luckily for you, this article will show you everything you need to know.

But before we dive right into it, let's clear the basics out of the way.

The elements of UI design


When we talk of UI we refer to a group of visual elements that the user interacts with. Unlike interaction design, the users see and use the components that make up the UI.

These elements of UI include:

  • Typography
  • Color
  • Images and illustrations
  • Icons
  • Buttons

Therefore UI design refers to how the designer creatively combines these components in a way that results in a positive experience for the user through great aesthetics, and psychologically backed and well-structured designs.

Wondering how to do all that? Read on to find out amazing UI design tips.


What are the principles of UI design?

The principles of user interface design are rules or UI design guidelines that help designers to create interfaces that effectively align with and impress the users.  

You can think of these principles as frameworks based on generally accepted best practices in the visual design field.

If you observe a majority of interfaces side by side, you will notice that some of them really do stand out. At first glance, it might be unclear why? But on closer inspection, you will notice the patterns that repeat themselves.

Following the best UI design guidelines will give your designs a clean and powerful look. Most of these principles are based on broader UX heuristics and theories we will discuss.  

There are so many overlapping UI design principles— because there are several ways to look at the foundational UX theories. But popular among them include:

  • Consistency
  • Emphasis
  • Hierarchy
  • Unity and Variety
  • Scale and proportion
  • And the gestalt principles

Before we go on to look at them, let us understand some of the fundamental UX heuristics. By doing this, you will get a deeper understanding of the reasoning behind some UI design choices of top brands.  

What are the usability heuristics?

Introduced by Jacob Nielsen, the ten usability heuristics known popularly as the ten laws of UX are a group of recommended UX best practices that cover crucial aspects of human-focused UI design.

These ten laws of UX are referred to as heuristics because they are rules of thumb that can aid UX designers in making the best design decisions, and fast.

Note that the heuristics apply to a much broader range; some of them, however, are the fundamental rules behind UI design practices.

Below are the ten usability heuristics:

1.User control

This rule states that users should control the outcomes when interacting with an interface. They should be able to easily use emergency or quick exits to reverse an action.

For instance, the screenshot below of Twitter's homepage shows a Turn on notifications pop-up.


The user can simply cancel this by using the Not now button. However, there is also a cancel ❌ icon at the top left. This might seem redundant but Its role is to re-emphasize user contro

2.Match between system and real world

When designing interfaces, use languages and concepts the user is familiar with, you don't want a situation where the user is lost.

3.Visibility of system status

Use timely feedback to inform users about what is going on, or the state of an operation, as much as possible. Don't leave them wondering what just happened or what will happen next.

A clear use of this rule is seen in the image above. The system wants the user to understand the result of their action and gives them room to cancel.

4.Consistency and Standards

Consistency is a crucial aspect of design. It is not a great practice to use different visual elements for exactly the same purpose. That is why there are entire design systems built to ensure consistency all through. It is advisable to follow platform conventions as well.

5.Error prevention  

Make interfaces that are as error-free as possible. Avoid known practices that can introduce unwanted errors.

6.Recognition rather than recall

Make options visible and do not make users recall information when you can simply provide options and hints.

7.Flexibility

Shortcuts enable familiar users to perform functions faster. Include but hide them from novice users.

8.Aesthetic and minimalist design

This rule is all about simplicity. Interfaces should not contain irrelevant information.  In design, there is a popular saying that less is more. Avoid visual clusters and ensure your interfaces make use of interesting visual elements.

9.Error management

Help users easily recognise errors when they occur, diagnose them quickly and recover from the unwanted state. Use plain language for error messages.

10.Help and documentation

It is best if no additional explanation is required to navigate your product, which will be the case if it's intuitive. However, include easy guides when necessary to help users understand and troubleshoot problems.
So what are the UI design principles? Read on.


The basic UI design principles

Some of the widely used UI principles include the following:

Consistency  

In visual design, it is necessary to use elements in a way that makes sense to the users. An icon that opens a menu on a page should not lead to a cart on the next page.

Consistency enables users to familiarise themselves with all the components of a system and therefore, easily perform operations without hiccups.

A way of ensuring consistency is by following platform standards, e.g, Google's Material Design System.

For instance, smartphone users are used to a home icon that navigates them to the home screen when clicked. If you decide to use the home icon in a "unique" way in your app by directing the user to a settings page instead, this can confuse the user and ultimately cause a bad experience.

While the consistency principle might not directly impact the aesthetics of the product, it reduces cognitive effort and also prevents possible errors.

Emphasis

Show what is more important by making it stand out to the user. Emphasis means making sure the user will, at a glance, understand the purpose of a page or find whatever information they need.

There are several ways to create emphasis, and one of them is visual weight. By increasing the size of a visual element, you make it stand out from other similar elements and therefore ensure it captures the user's attention.

Other ways for emphasis include color and size.

A popular use of the emphasis principle is seen in typography. Most web pages have important headers separating other content. These headers are made to be bigger than other text to draw the reader's attention with ease.

Below is a screenshot of Medium's homepage.

UI design principle of Emphasis

A subtle but noticeable green color separates the top part of the page from the rest of the content. This color adds more emphasis to that area.

Hierarchy

Hierarchy in UI design is about placing elements in a visual hierarchy of importance. This creates an intuitive interface enabling the user to make out the most important elements first.

Just like emphasis, hierarchy is all about importance. Helping users navigate to the information they need.

UI designers use these principles to ensure a logical structure that reduces time spent making out what does what in the system.  

For instance, the screenshot below is of the Maze homepage.

UI design principle of hierarchy
UI design principle of hierarchy

Notice how the fonts are of different sizes. While it adds to aesthetics, the main purpose of this typography style is to create a visual hierarchy.

Unity and Variety

The basis of the unity principle is harmony. Usually, a design will consist of several elements, some having similar or different colors, scales, emphasis, etc. Unity refers to how well these components work together to ensure a pleasant overall design.

For the variety principle, the contrast is the case — leveraging the differences and uniqueness of the elements to spice up the design or achieve other desired effects.

UI design principle of Variety
UI design principle of Variety

The Variety principle is seen in the way this site uses different background patterns and colors.

Scale and proportion

To create a beautiful design, the UI designer needs to ensure that the elements used are of a reasonable scale and proportion relative to each other.  

Scale refers to using size differences between elements to emphatize their importance.

UI design principle of Scale
UI design principle of Scale

In the image above, notice how each job post is held in a white "container" having the same size. At a glance, users can tell they are all job posts.

Contrast

The contrast principle is about making elements stand out or differ from each other by using vividly different colors.

The contrast principle has two major benefits. First, by using strongly contrasting colors, you can help the user differentiate elements easily and make out what is important. This increases accessibility.

For instance, users with poor sight might struggle to read faint fonts on a white background. Having your users strain their eyes before they can make sense of your content is poor UX.

In fact, there are online tools that exist solely to check the contrast level of your texts and recommend changes, e.g, webAIM contrast checkeror another tool like the Accessibility contrast checker by EXPERTE. The second is that contrast if used properly gives your pages a more powerful and visually appealing look. It is good for aesthetics.

Below is Parabola's website showing good use of contrast between black text and yellow background.

Alignment

Alignment means arranging elements on the page in an orderly manner along lines. This can be vertically or horizontally.

Alignment helps create balance in design. Also, when elements are properly aligned, it indicates that designers meticulously planned the structure of the UI and gives a clean look.

Improperly placed elements, on the other hand, can get users worried about the amateurish interface.

Always ensure the elements on your page are properly aligned. Most design tools have options in place to help designers with alignment, e.g, grid lines and rulers.

The gestalt principles

The gestalt principles are a group of psychological principles used in UI design. They are called "gestalt"—German for shape—  because they are principles guiding how the human mind interprets shapes or forms.

Knowledge of these rules can enable you to design interfaces that leverage the curiosity and biases of the mind, delivering more engaging and thoughtful visual designs.

The Gestalt principles include:

Similarity - The psychology behind similarity is that the human brain wants to group similar-looking objects as having the same qualities.

In UI design, you can group elements using color, size or other visual qualities. Similar elements should perform similar functions.

Common region - Objects that share a common space away from others appear as having more in common with themselves than with the rest.

Using whitespace to separate similar elements from others can achieve this in design.

The input fields on the left share a common region
The input fields on the left share a common region

Proximity - This is a bit similar to the common region principle. Proximity posits that the brain classifies objects by closeness to each other.

Placing elements that perform similar functions close is good practice as this is what the user expects.


Closure
- we are wired to want to fill in the blanks. An incompletely drawn image would get your brain's creative juices flowing, and you come up with a complete picture.

This is an engaging technique popular in the design of logos, images, etc.


Continuation
- just like closure, the brain wants continuity and will follow the lines and paths in the design.


Symmetry and order
- a disorganised design will mean more work for the user because the brain takes more time to make sense of elements with no symmetry or structure. Balance is an important goal for designers.


Benefits of UI design principles

Asides from being simple rules to follow in creating UI designs with ease, the UI principles have some other benefits:

Creates standards - These principles are generally accepted and used widely. For consistency purposes, it is ideal to follow them.
Better experience for the user - the UI design guidelines are backed by psychological theories and of course, research on user behaviour. They are not guaranteed to be the solution to all design problems, though.
More engagement - well-designed interfaces encourage more engagement from users. A poorly designed website, for instance, might experience high bounce rates due to unsatisfied users.
Effective solution to user needs - coupled with proper user research and other components of the design thinking framework, UI best practices are part of the crucial elements needed to deliver solutions that satisfy users.

How can I improve my design?

A bad design is most likely one that doesn't follow the UI design tips stated here. Yes, there's a lot of creativity needed in a job as a designer but these principles make your job easier.  
To improve your designs both aesthetically and user experience-wise. First, ask yourself if your design meets the recommendations here.

Are you observing good contrast? Are your icons properly aligned? What of the typography?

Following the UI design guidelines closely can greatly improve your work.  Alternatively, you can learn by observing and breaking down the works of established experts in your field. By following and replicating their designs you gain insights into how they think and apply UI best practices.

What are the 4 categories of UI elements?

The four major categories of UI elements are:

Input controls: enables users to pass information into the system. They are important for maintaining interactivity and personalized experiences. Examples include forms, drop-down menus, text fields, etc.
Navigational components: enables users to move from one page to another within a website or app. Depending on the platform, you can use different icons for navigation, e.g, Android's Hamburger menu.
Informational components: share information with users. They are important for feedback.  Examples are pop-up menus, dialogs, etc.
Containers: these are elements that hold related objects together. Examples include cards, menus, etc.

Conclusion

The UI design principles help designers create thoughtful interfaces. It is important to understand and use them as guidelines while injecting your creativity into the process.