What is Heuristic Evaluation?
Heuristic evaluation is a usability engineering method for finding usability problems in a user interface design, thereby making them addressable and solvable as part of an iterative design process. It involves a small set of expert evaluators who examine the interface and assess its compliance with “heuristics,” or recognized usability principles. Such processes help prevent product failure post-release.
Typical usability evaluations of interfaces can be long, difficult, expensive and time-consuming processes that often intimidate developers. They are hence often ignored—at the cost of delivering software that suffers from usability issues and results in frustration and errors during use. To overcome the issue partially, Jakob Nielsen (pioneer of web usability) has advocated for “discount usability engineering methods”—i.e., methods that developers can adopt which are cheap, fast and easy to use. Heuristic evaluation is one of these methods.
In a heuristic evaluation, a set of evaluators assess a designed interface for compliance against an agreed set of principles. Each evaluator works alone and goes over the interface multiple times. At length, the evaluators produce reports which are then discussed, the end result being a list of usability problems (and their causes) to be addressed. In heuristic evaluation, evaluators can supplement sets of general design principles with additional heuristics that match the product category or its characteristics, as necessary. The number of evaluators for each project may vary, but using about five of them is generally recommended, as this number has been shown to be able to discover approximately 75% of all usability issues. Because evaluators are inspecting the interface and not actually using it, heuristic evaluation is suited to early use in the development life cycle, where the interface may consist of nothing more than paper-only designs. By its nature, such evaluation facilitates catching oversights before they become truly problematic.