10 Usability Heuristics according to Nielsen
Jakob Nielsen, the founder and head of the Nielsen Norman Group, is a Danish author, speaker and consultant in the field of software and web design usability. He is one of the pioneers in the field of usability research, having achieved wide media attention with his articles on usability.
Among other things, he is known for his rigorous critique of popular websites. He also invented several usability methods, including heuristic evaluation.
Heuristics comes from the ancient Greek εὑρίσκειν (heurískein), and means "to find" or "to discover." It is a method of assessing usability formatively, before the overall system is completed.
In 1995, more than twenty years ago, Jakob Nielsen formulated his 10 principles for interaction design under the title "10 Usability Heuristics for User Interface Design".
So what are the rules of thumb for usability?
1. Visibility of status
The application always informs the user about what is happening - in a timely manner and through appropriate feedback. An example of this is a progress bar when filling out a form or feedback when selecting a password, if this password has to comply with certain password rules.
2. Correspondence between application and reality
The application should speak, with adapted words and concepts, the language of the user, not the language of the developer. Phrases that may sound sensible in technical jargon among colleagues are confusing to average users. "Everyday language" helps users remember processes within applications and makes them more intuitive to use.
3. User control and freedom
Users make mistakes, yet should always retain a sense of control over their input, according to Nielsen. They should be able to undo actions or start over. Nielsen calls this an "emergency exit." This emergency exit gives users freedom and prevents frustration in the process.
4. Consistency and standards
Users should not have to wonder whether terms have the same meaning. Users have certain expectations of an application that have evolved from experience with other applications. Standards help to navigate intuitively through an application. Design innovations are best when they are linked to already established patterns.
5. Error prevention
Better than any good error message is a careful design that prevents errors from occurring in the first place. Clear communication and design that makes it difficult for users to make mistakes is essential.
6. Recognition > memory
The cognitive load of the user should be reduced by making objects, actions and options visible. Reminders of previous steps should not be necessary. Instructions should be directly visible or easily retrievable.
7. Flexibility and efficiency
Shortcuts and other shortcuts speed up operation for advanced users. They should be able to do customization so they can decide for themselves how the product should work.
8. Aesthetic and minimalistic design
Dialog boxes are free of superfluous or rarely needed information. This is because any additional information reduces the perception of relevant content. This means that the design does not distract from the content and the design elements support the user's goals.
9. Help in recognizing, evaluating and correcting errors
Error messages should be kept as simple as possible and explain what exactly the problem is. Offering suggestions to users helps them learn from mistakes.
10. Help and documentation
Help should be provided in both proactive and reactive forms. Proactive help should be provided to help users learn how to use an application, while reactive help should be provided to users in the process and in problem situations.