Nielsen's heuristics

They were formulated by Jakob Nielsen, a usability specialist and co-founder of the Nielsen Norman Group. A first version appeared in 1990 with Rolf Molich, then Nielsen refined the list of ten principles in 1994. The ten heuristics have remained unchanged since then, with only their examples updated.

Both frameworks come from the same approach, usability studies carried out methodically, and differ in their level of detail. Nielsen's ten heuristics are general principles, quick to memorise and to apply. Bastien and Scapin's eight criteria, broken down into eighteen sub-criteria, are finer-grained. You often run one for a quick evaluation, the other for an in-depth audit.

Nielsen recommends three to five evaluators. A single expert spots about a third of usability problems, whereas a small group, by combining different viewpoints, identifies the vast majority of them. Beyond five, the gain becomes marginal relative to the cost.

No, the two are complementary. Heuristic evaluation, carried out by experts, quickly spots known design flaws without recruiting anyone. User testing, for its part, reveals real usability blockers that experts don't always anticipate. One doesn't remove the need for the other; it prepares it and completes it.

Yes. They are general principles, as valid for a website or a business tool as for a mobile application. Their formulation doesn't depend on any technology; only their implementation adapts to the context of use.