Jakob Nielsen, co-founder of the Nielsen Norman Group, devised a set of ten usability heuristics as a set of general principles for good interaction design.

Like the principles for good user experience described in the last exercise, these heuristics are intended as rules of thumb. They help designers assess where a design is excelling and falling short, and what trade-offs are being made in a design process.

Take a look at the full list of the ten heuristics on the Nielsen Norman Group’s website. Here are some to highlight:

• Visibility of system status: The design should always keep users informed about what is going on, through appropriate feedback within a reasonable amount of time.
• Consistency and standards: Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform and industry conventions.
• Flexibility and efficiency of use: Shortcuts, hidden from novice users, may speed up the interaction for the expert user such that the design can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.
• Help users recognize, diagnose, and recover from errors: Error messages should be expressed in plain language (no error codes), precisely indicate the problem, and constructively suggest a solution.

The heuristic evaluation is a relatively quick and flexible method of usability testing, compared to other methods such as user testing. During this process, a group of expert evaluators classifies usability problems based on the ten heuristics. Heuristic evaluation is highly based on the evaluators’ expertise and is not a replacement for testing a product with real users.

Nielsen’s heuristics have inspired others to create alternate heuristics for assessment within different fields, such as humane design and persuasive health technologies.