10 Usability Heuristics Every Designer Should Know
Jakob Nielsen and Rolf Molich (Danish web usability experts and consultants) published a set of principles or heuristics based on their many years of usability engineering experience. These principles are widely used in the design industry to create effective UI design.
Here is the list of 10 usability heuristics for interaction design described by Jakob Nielsen and Rolf Molich.
1. Visibility of system status
Users should be kept informed about their system status until a process is completed. An example of this is the progress loading bar you see on websites – the bar displays a load percentage to demonstrate how much progress has been made and is still to go.
2. Match between system and the real world
Concepts and information should be familiar and easily understood by all users to avoid confusion. For example, when you see a trash bin icon, you know you can move unwanted files there to dispose of them. This is consistent with the purpose of a trash bin in real life, therefore familiar to all users.
3. User control and freedom
Sometimes users accidentally click something they didn’t intend to. It’s important to have both undo and redo functionalities within an interface to remedy the mistake. Every system should offer a clear opportunity to undo errors quickly and conveniently (a simple example of this is the back arrow).
4. Consistency and standards
Avoid confusing users by using different terminology or icons. Be consistent. Users should have confidence that words or actions used in one area of design will have the same meaning or action in another area.
5. Error prevention
Notify users of errors. For example, if a user is typing in a postal code in Canada, but accidentally enters four characters instead of six, they should receive a notification alerting them that the postal code is incorrect. In this situation, the user should not be able to proceed until a six-digit code is entered. If the action is allowed to continue, despite a potential error, the user should be notified and warned of potential consequences.
6. Recognition rather than recall
Recall requires more effort than recognition. Provide users with something they can recognize, instead of asking them to recall something they’ve seen before. For example, on an online payment form, structure the form to show labels above the field as the user is typing. This helps the user to remember what information they are entering and can help avoid confusion, especially on longer forms.
7. Flexibility and efficiency of use
Users shouldn’t have to spend much time familiarizing themselves with your product or system in order to use it properly. And a good user interface contains functionalities that both inexperienced and experienced users can use. To achieve this, you might enable power users to create shortcuts to perform tasks quickly, but not require these shortcuts for less frequent users.
8. Aesthetics and minimalist design
Avoid irrelevant information. In other words, don’t clutter your interface. Use white space to create balance within your design and limit the number of colours to avoid distraction.
9. Help users recognize, diagnose, and recover from errors
Error messages should be easily understood. They should include a description, not just a code. The description should explain what the problem is as well as a recommendation on how to fix or recover it. The contents of the messages should not instill panic, but instead provide users with assurance that there is a convenient, alternative solution.
10. Help and documentation
Documentation provides users with access to additional information where they can learn how to use and navigate a product effectively. The more helpful information that’s provided, the more likely the user will learn and use the product for the long-term. FAQ pages, learning centers, support, and help centers are all examples of documentation.