Casual design critique: a quick design review in which the design is analyzed at a higher level to determine whether it meets usability standards and provides a good experience. 1-3 hours.
Heuristic evaluation: a type of design review in which the design is evaluated for compliance with a set of heuristics such as Jakob Nielsen’s 10 Usability Heuristics. It can be done on the system or a section therein. 1-2 hours each.
Expert review: a design review in which a system (such as a website or application) is checked for a variety of design challenges, like: Information Architecture, Interaction design, Visual design, Design Patterns, Usability, Branding Guidelines, Accessibility. 10-40 hours.