Usability is a measure of how well a specific user in a specific context can use a product/design to achieve a defined goal effectively, efficiently and satisfactorily. Designers usually measure a design’s usability throughout the development process—from wireframes to the final deliverable—to ensure maximum usability.
“Usability is about human behavior. It recognizes that humans are lazy, get emotional, are not interested in putting a lot of effort into, say, getting a credit card and generally prefer things that are easy to do vs. those that are hard to do.”
— David McQuillen, ex-Swiss banker and founder of Sufferfest cycling workout resources
People often confuse usability with user experience and ease of use. Usability is a component of user experience (UX) design. According to the Nielsen Norman Group—a leader in the UX field—usability is the second level in user experience. It comes after utility and before desirability and brand experience. So, after you’ve determined that your item can solve users’ problems, you must address its usability. A design’s usability depends on how well its features accommodate users’ needs and contexts. Therefore, you are responsible for your design’s usability. It should contain these elements:
Effectiveness—It supports users in completing actions accurately.
Efficiency—Users can perform tasks quickly through the easiest process.
Engagement—Users find it pleasant to use and appropriate for its industry/topic.
Error Tolerance—It supports a range of user actions and only shows an error in genuine erroneous situations. You achieve this by finding out the number, type and severity of common errors users make, as well as how easily users can recover from those errors.
Ease of Learning—New users can accomplish goals easily and even more easily on future visits.
When they first encounter an interface, users should be able to find their way about easily enough to achieve objectives without relying on outside/expert knowledge. A design with high usability guides users through the easiest and least labor-intensive route. So, you must leverage a deep understanding of users’ contexts. To do that, you must accommodate their limitations, such as their environment, likely distractions and cognitive load.
You should first focus on how well your design will flow in context. That means you focus on it as a whole—not on its parts (e.g., individual webpages)—and make content simple. Therefore, ensure you:
Work with a clear understanding of users’ goals and show it in your design.
Mimic the real world regarding concepts, icons and language.
Present instantly understandable, jargon-free messages and actions users can take—one chief action per screen.
Limit options to give a strong information scent on an uncluttered display—show essential information for completing tasks.
Keep content consistent.
Follow established norms regarding function and layout (e.g., logo positioning, tappable buttons).
Use proper font size, color, contrast, whitespace, etc. to:
combine aesthetic appeal with scanning readability,
present a clear, logical information hierarchy,
design for accessibility.
Use chunking and emphasize key information at the beginning and end of interactive sequences.
Offer informative feedback about system status.
Include helpful navigation systems and search functionality.
Allow for customizable controls, including shortcuts.
Avoid disruptions – e.g., forced logins/pop-ups.
Make forms easy to complete.
Include warnings and autocorrect features to minimize errors.
Make errors easy to diagnose.
Offer easy-to-understand help documentation.
Show clear contact options.
Provide a back button to undo actions.
Include ALT tags to show more information about images.
Consider server abilities regarding page-loading time and downtime.
Beware of in-app browsers and restrictions (e.g.,scrolling) in mobile design.
Make links active.
Describe links accurately.
Use user personas.
Do thorough usability testing
Users should feel immersed and in control of products/designs that predict their actions and help them get things done properly and fast. If they stop to think about what you’re showing them, they’ll start losing trust. Overall, they should find it all satisfying—if not pleasing.
Our course-selection page anticipates users’ needs by clearly guiding towards goals via filters.
The Interaction Design Foundation has a wealth of material on usability, including this course: The Practical Guide to Usability
See important points about desktop vs. mobile usability
Read Smashing Magazine’s extensive list of usability considerations
Here’s an exemplary, insightful walkthrough of an app’s usability
Usability focuses on how intuitive and user-friendly a design is. Taking an e-commerce site as an example:
- Is it effective? Can users find what they are looking for and place an order? Does it meet their expectations?
- Is it efficient? Is it relatively quick and easy to carry out tasks? Do users end up backtracking on the site or wasting time in numerous layers of navigation?
- Is the experience satisfying? Are users happy or frustrated? Are they confident that their order has been successful?
Usability encompasses three core factors: effectiveness, efficiency, and satisfaction. Effectiveness refers to a user's ability to complete a task using the product. Efficiency focuses on the speed and resources used to achieve the task. Lastly, satisfaction measures how pleasant and satisfactory the user experience is when interacting with the product. Ensuring these factors are optimized contributes to a user-friendly design and a positive user experience.
Desirability and usability are distinct aspects of user experience. Usability focuses on how easy and intuitive a product is, ensuring users can complete tasks efficiently. On the other hand, desirability relates to the emotional response a product evokes, encompassing its aesthetics, appeal, and the pleasure users derive from using it. While usability prioritizes functionality and user-friendliness, desirability emphasizes creating a memorable and enjoyable user experience. Explore Interaction Design Foundation's article on "Usability vs. Desirability."
No, usability and usefulness are distinct concepts in design. Usability refers to how easily and effectively users can interact with a product, and how satisfied they are with that interaction. On the other hand, usefulness addresses whether the product fulfills a specific need or solves a meaningful set of problems for users. A product can be usable (easy to use) but not useful (doesn't meet user needs). For a deeper dive into their differences and importance, consult the Interaction Design Foundation's article, "Useful, Usable, and Used: Why They Matter to Designers."
No, usability and accessibility are related but distinct concepts. As Don Norman points out, accessibility is about making things easier for everyone, especially those with reduced abilities. Think of accessibility as usability's close cousin. Usability aims to ensure that a product is straightforward and efficient for everyone, whereas accessibility ensures that even those with disabilities can use the product. While optimizing for accessibility often improves usability, enhancing usability doesn't necessarily make something accessible. For example, an optimized website for accessibility might include features like video transcriptions, image captioning, Alt attributes, and semantic HTML. Both usability and accessibility aim for a more user-friendly experience, but accessibility places special emphasis on inclusivity for all user types.
No, usability is a facet of user experience (UX), but they aren't synonymous. Usability focuses on the ease of use and effectiveness of a product. It evaluates how user-friendly and efficient a product is for its users. In contrast, user experience encompasses a broader range of factors, including the emotions, perceptions, preferences, and responses of users when interacting with a product. While usability is crucial, UX considers the entire journey and holistic experience. For a comprehensive understanding, refer to the Interaction Design Foundation's article, "Usability: A Part of the User Experience."
To analyze usability, evaluating how effectively users can interact with a product is crucial. Simply conducting evaluations without implementing improvements can lead to inefficiencies. Think of it like manufacturing: if a product has flaws, merely ramping up quality checks doesn't address the root issues. While usability testing is invaluable, there are other answers. The goal is to pinpoint and correct design shortcomings, optimizing the overall user experience. Check out our usability testing course for a deeper dive into this subject.
For an in-depth understanding of usability, consider two courses from Interaction Design Foundation. Firstly, The Practical Guide to Usability offers a comprehensive overview of usability principles and techniques. Secondly, delve into Conducting Usability Testing for hands-on insights into user-centric evaluations. These courses equip you with the expertise to create user-friendly designs and analyze their effectiveness. Dive in and enhance your usability knowledge today!
Here’s the entire UX literature on Usability by the Interaction Design Foundation, collated in one place:
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