Heuristic usability evaluation technique

Heuristic evaluation: a systematic inspection of a user interface design for usability.
Perform heuristic evaluation by judging what is good and bad about the interface. Use usability guidelines, intuition, and experience as the basis.
Each individual evaluator inspects the interface alone to minimize bias. Combine and aggregate the findings. Best practice is to go through the interface twice, first for the flow of the interaction and scope, and second to focus on specific interface elements such as visual design, language, consistency, style. Perform representative tasks to exercise the interface.
Not as rigorous as usability testing, heuristic evaluation can be effective and efficient, particularly when there are several evaluators and when the evaluators have expertise in usability and/or the type of interface being evaluated.

Reference:
Nielsen & Mack, Usability inspection methods, 1994.