Product expert reviews, sometimes referred to as heuristic evaluations, are professional assessments of a current product, which are performed by design experts for the purpose of identifying usability and user experience issues.

The thinking behind the expert review technique is very practical. Experience designers have the expertise to assess the experience quality of a product in a systematic way, using a set of accepted heuristics.

A heuristic is a rule of thumb for assessing products. For example, the 'error prevention' heuristic deals with how well the evaluated product prevents the user from making errors.

The word "heuristic" often raises questions, and the method has been criticized for its inherent weaknesses due to:

• Subjectivity of the evaluator
• Evaluator's lack of domain expertice relevant to the evaluated product
• Cultural and demographic background of the evaluator

These weaknesses increase the probability that an expert evaluation would reflect the biases and preferences of the evaluator and result in different conclusions from different evaluators.

Still, expert evaluations, especially if conducted by two evaluators, are an effective tool for experience practitioners who need a fast and cost-effective assessment of a product, particularly digital interfaces.

Jacob Nielsen developed the method in the early 1990s. Although there are other sets of heuristics, Nielsen's are probably the most well known and commonly used. His initial set of heuristics was first published in his book, Usability Engineering. It is presented here verbatim, since there is no need for modification:

• 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 user's 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. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.
• Recognition rather than recall: Minimize the user's memory load by making 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 recognize, 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.