And precisely for this reason, we need to bring up the question: how can we make the experience of these users (people who use the system) more intuitive and straightforward, increasing satisfaction and reducing friction between them and the screens? One way to promote this ease is through general principles of usability, or heuristics, created by Nielsen.
Jakob Nielsen holds a Ph.D. in human-computer interaction, considered a reference when it comes to the ease with which people use technology (usability). He is also the founder of the Nielsen Norman Group, which provides consulting, research, courses, guides, and more in the field of user experience.
Nielsen developed 10 heuristics that represent good practices to offer the best possible experience to users, as a simpler and less costly way of evaluating screens. Today, we will discuss each of them and how we can perform heuristic evaluations of the interfaces we work with.
1. Visibility of system status
We make decisions based on the information provided to us at all times, and when we interact with a system, we need to know its current state. Whether it's knowing how much time is left for a download to complete or if a post on a social network was successful, we seek confirmation and security provided by timely feedback. Similarly, if there's an error, a warning feedback gives the user an opportunity to correct it.
2. Match between system and real world
The text displayed on a system's screen should be easily understandable for the person using it. It doesn't make sense to use medical jargon in an interface intended for engineers. Terms should be common and familiar to the user's everyday language. This heuristic goes beyond just text; the way information is presented on the screen should resemble its real-world counterpart. For example, when choosing a seat on an airplane, we see a visual representation of the plane's seats rather than just a list of numbers and letters. This familiarity provides security to the user and makes the screen easier to navigate, showing empathy from the system towards the user.
3. User control and freedom
Incorrect choices made by the user on the screen, whether due to a wrong click or even reconsidering a decision, should be correctable. Being able to exit from a screen that was opened, go back, cancel, and undo actions all give the user control over the system and avoid a feeling of being trapped. Additionally, this heuristic allows users to explore the screen before committing to an action, reducing frustration in the learning curve. Thus, these actions should be easily discoverable on the screen and have clear consequences.
4. Consistency and adherence to standards
Maintaining internal consistency means ensuring that colors, icons, and other patterns have the same meaning whenever they are seen within the system. External consistency involves using standards commonly present in other websites, systems, or applications. As Nielsen puts it, "users spend most of their time on other sites, not yours, so making your site look like everything else reduces their cognitive load." Examples include using a magnifying glass icon for search or placing the shopping cart in the upper right corner on e-commerce sites.
5. Error prevention
The system's screen should help the user avoid errors, whether they are minor slips or more significant mistakes. Users can be warned when they are making an error, like entering a future year as their birthdate, needing to confirm a destructive action, or being able to undo the sending of an email.
6. Recognition rather than recall
Recognition is one of the most important heuristics as it requires less mental effort from users by relying more on cues present in the context. For example, when we see a familiar person, we recognize them, but recalling their name is more challenging as we rely entirely on our effort to remember it correctly. Therefore, promoting recognition over recall reduces user effort and improves the experience.
7. Flexibility and efficiency of use
A system should be flexible enough for both new and experienced users to use it with maximum efficiency. New users shouldn't need to know all the shortcuts and functionalities of a system when they use it for the first time since it can be overwhelming. At the same time, experienced users can take advantage of shortcuts to speed up routine activities. This means there can be more than one method to perform tasks, and users can choose based on their needs. Shortcuts should be easy to discover but not intrusive on the screen, such as when hovering the mouse over a "Copy" button and getting a tooltip with "Ctrl + C."
8. Aesthetic and minimalist design
The design of a system should be attractive to capture people's attention, reinforce the brand's identity, and create an impression that it works well. At the same time, it should be minimalist to reduce unnecessary information noise and visual clutter, while focusing on relevant information and actions. This way, users are guided to what they need, thus avoiding frustration.
9. Help users recognize, diagnose, and recover from errors
When a system displays an error message, it should be visible with elements such as icons and colors to make the error clear. It should also explicitly state what is wrong. Vague messages or technical jargon from development do not help users understand what is wrong and what action to take. Additionally, offering alternatives for users to choose a solution, when applicable, is a good practice. This can be done through a button that takes the user back to the homepage or suggests changing filters, for example.
10. Help and documentation
Ideally, a system should be so easy and intuitive that no help documentation is needed. However, with increasingly complex systems, some help documentation may become necessary. In such cases, it's a good practice to provide help to users when they need it, focusing on the tasks they want to perform. If there is a help page, it should be searchable, allowing users to find what they need easily. Nielsen recommends presenting information step by step for easy comprehension and keeping it concise so that users can resolve their problems quickly.
These principles are not strict rules and may not always be applicable to your context. Nevertheless, they are the result of user experience studies conducted by experts in the field. Using these heuristics, we can evaluate screens and interactions of a system, comparing what we see with the general principles and identifying possible ways of improvement. Ultimately, when we use a digital product, we want it to work well for us, rather than making us struggle to use it.