Nielsen’s 10 heuristics, or timeless principles of UX
In the world of UX, are there timeless rules that must be followed every time to achieve a satisfactory result? Both yes and no. The answer is not clear-cut. It is worth mentioning, however, that there is a kind of a decalogue, which for many UX designers is a kind of a checklist for evaluating the degree of usability of an application or a website. This decalogue is Nielsen – Molich’s 10 usability heuristics (Nielsen’s 10 heuristics).
To answer the question what are usability heuristics one has to go back to 1990, when Jakob Nielsen and Ralf Molich presented a set of 10 rules for human-machine interaction. Nielsen is not as famous as IT celebrities such as Gates, Jobs or Ellison, but the impact his heuristics have had on the approach to developing applications and websites is invaluable. Sam Nielsen is a controversial man because, on the one hand, he has a wealth of experience (he has worked m.in. He is a computer scientist (on the one hand a PhD in IT sciences from the Danish Technical University and on the other a hardcore IT conservative and author of many debatable statements. To sum up briefly – 32 years ago general rules were created to evaluate usability of developed products.
10 Nielsen heuristics
1. Visibility of system status
The system should always let users know what is happening at any given moment. At any time during the execution of any operation, the user should have precise information about its status. Good examples are progress bars, distinctions in the form of button color changes or highlighting. Another good example is a visual presentation of the availability of goods in an online store or the availability of seats in a ticket reservation system.
2. Match between system and the real world
The system should speak the language of the user – familiar words, concepts and phrases. Avoid incomprehensible symbols, complicated phrases and jargon understandable only to people who are very deep into technical aspects of a given technology. Also, all icons and the ordering of the interface should refer to generally accepted standards – examples are the play and stop button in music players or the trashcan icon for removing objects.
3. Give the user control and freedom
Users often perform certain actions by mistake. Then they need something like an “emergency exit” to go back to the previous stage of an operation, make a correction, or simply close an annoying pop-up. Sometimes a properly placed “X” icon or visible “cancel” button is sufficient. Other times, the solution to the “limited freedom” problem is to be able to go back a few steps in the form to correct one of the completed pieces of information without having to start the whole process over again.
4. Consistency and standards
Consistency above all! Users should not have to wonder if different words and actions mean the same thing and lead to the same goal. Experience tells us that the shopping cart icon will indicate the products we want to buy, a magnifying glass will allow us to search for the information we need, and blue underlined text can be clicked.
Nielsen divided consistency into two types: internal and external. Internal consistency refers to consistency within a product or an entire family of products. It is about sticking to a uniform design – use of uniform fonts, colors, page layouts, etc. A good example of internal consistency is the Office ribbon – several products with the MS logo, and yet we can change the font in each of them in almost the same way.
External consistency refers to the overall industry standards. Users of competitive products will want to transfer their habits to our product as well. Examples? Menu placed in the same place on the page, large and clear search bar, logo placed in the upper left corner.
5. Prevent errors (Error prevention)
Error messages are important, but a design that prevents errors from occurring is preferable. A variety of tools and techniques can be used, but the main rule is: eliminate costly mistakes first, then take care of the little things. A good example of error prevention is the need to confirm each operation – this eliminates the impact of accidental clicks throughout the process. Another solution are hints in the forms on how to enter data, e.g. height in centimeters or phone number without spaces.
6. Recognition rather than recall
Relieve user memory by displaying objects, actions and options. All necessary information should be visible on the screen. The user should not have to remember throughout the entire process what he did at the beginning. Good examples of relieving the user’s memory are suggestions for search terms when text is entered and a list of recently viewed products.
7. Ensure flexibility and efficiency of use
Various shortcuts and options added to the interface to speed up operations for both novice and experienced users. Examples are checkboxes “select all”, quick links, remembering filters or the ability to add products to the favorites list. Personalization and the ability to customize applications to user preferences is basically a standard, because nothing is as annoying as having to perform repetitive actions every time, such as manually setting filters or searching for products we’ve already ordered a thousand times.
8. Aesthetic and minimalist design
Many believe that this heuristic perfectly captures the spirit of Nielsen. In the name of the “less is more” principle, each element should not contain unnecessary or distracting information. Each “additional” information reduces visibility of the “basic” one – Therefore, messages should be concise, and each piece of information should serve a specific purpose. Minimalism is to ensure readability and clarity – usability is a priority, aesthetics cannot limit it. Probably the best examples are simple and legible forms, with appropriately selected, subdued color palette, supplemented only with minimalistic symbols and icons.
9. Help users recognize, diagnose, and recover from errors
In short, it’s all about error handling. Error messages should be expressed in plain language (preferably tailored to the user), precisely identifying the problem and indicating a solution. A perfunctory “an error occurred”, “the process failed” or “error B0110” is definitely not enough and not what the user expects. It’s worth to take care about the right setting of an error message – a red frame, red font or an exclamation mark icon in the message strongly suggest that something has gone wrong. Model examples are messages about an already taken user name together with a suggested name. Another example might be a search engine correcting a spelling error in a query entered by a user.
10. Take care of Help and documentation
Even if the interface doesn’t require extensive instructions, the user should still have access to documentation and help. Necessary information should be easy to find and include a list of steps that should be taken in a particular case. In theory, a useful product should be intuitive enough that the user does not have to study tutorials, unfortunately, this is not always possible to achieve. The “help” section, FAQ, possibly the most common problems, are examples of ways to implement these heuristics.
Nielsen’s 10 heuristics are not a compendium of knowledge on product usability, but a good introduction and starting point for usability testing. Everyone dealing with User Experience should treat heuristics as a checklist, which is an absolute minimum. The model developed by Nielsen allows to identify the vast majority of problems in a relatively simple way and provides a good basis for building their own good practices.