A heuristic evaluation is an analytic method by which multiple evaluators independently examine an interface against a set of principles and rules (called heuristics).
MeasuringU typically recommends a modified version of the original heuristic evaluation proposed by Molich & Nielsen. We use multiple (usually 2-4) evaluators who walk through common tasks and heuristic-based checklists to identify potential problem areas.
A heuristic evaluation generates problem lists similar to task-based usability studies sorted by problem severity.
A heuristic evaluation is most effective when done in conjunction with a task-based usability study. On average there is a 30% overlap in problems identified in heuristic evaluations and task-based usability studies on the same interface.