Heuristic Evaluation is a technique derived by the Nielson Norman group to assess the usability of a digital product. This is usually performed by a set of usability experts who reviews a product against the set of thumb rules derived the Norman group. These thumb rules at sometimes are revised by the usability engineers to accommodate more findings.
Why Heuristic Evaluation ?
The finest way to grade a product’s user experience or usability is by user testing it, which although consumes more resource produce the best results. User feedbacks are pricey and interpreting them is also time-consuming and not all user centered products have such freedom to these resources. At such cases Heuristic Evaluation of your product helps in minimizing the usability problems with a much lower consumption of your limited resources.
Studies also show how effective can these thumb rules actually be at discovering the usability issues. A team of four usability experts would be able to discover 77% of the problems during an evaluation process. Although it’s important to remember the fact that such percentage of success is possible only when the evaluation is performed by the experts and decreases as per the evaluators expertise and experience.
Jakob Nielsen’s ten usability heuristics
Most usability evaluators use a set of heuristics developed over 25 years ago by Rolf Molich and Jakob Nielsen. Before this work, lots of people had derived guidelines and principles for usability but there were often so many guidelines that an expert review could take many days to complete. (For example, Smith and Mosier’s Guidelines For Designing User Interface Software has 944 guidelines and remains the largest collection of publicly available user interface guidelines in existence.)
Molich and Nielsen’s ten guidelines are as follows.
- Visibility of system status: The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.
- Match between system and the real world: The system should speak the users’ language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.
- User control and freedom: Users often choose system functions by mistake and will need a clearly marked “emergency exit” to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.
- Consistency and standards: Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions.
- Error prevention: Even better than good error messages is a careful design which prevents a problem from occurring in the first place.
- Recognition rather than recall: Make objects, actions, and options visible. The user should not have to remember information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate.
- Flexibility and efficiency of use: Accelerators — unseen by the novice user — may often speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.
- Aesthetic and minimalist design: Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.
- Help users recognise, diagnose, and recover from errors: Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.
- Help and documentation: Even though it is better if the system can be used without documentation, it may be necessary to provide help and documentation. Any such information should be easy to search, focused on the user’s task, list concrete steps to be carried out, and not be too large.