Type of tests we are familiar with :

• Interviews/Observations: One-on-one sessions with users. At the Interview end of the spectrum, ask them questions about what they do. At the Observation end of the spectrum, watch what they really do. It’s often possible to conduct both types of session in the same on-site visit.


• Focus Groups: Often used in marketing well before there is any kind of prototype or product to test, a facilitated meeting with multiple attendees from the target user group.


• Group Review or Walk-Through: A facilitator presents planned workflow to multiple attendees, who present comments on it.


• Heuristic Review: Using a predefined set of standards, a professional usability expert reviews someone else’s product or product design and presents a marked checklist back to the designer.


• Walk-Around Review: Copies of the design/prototype/wireframe are tacked to the walls, and colleagues are invited to comment. (Post-It® Notes are good for this) It also works well when users are around for some other purpose, and this is the only way you can get their attention.


• Paper Prototype Test: Use realistic scenarios but a fake product. If possible, have a colleague "play" the insides of the product or software.


• Prototype Test: A step up from a paper prototype, this one uses some type of animated prototype with realistic scenarios.


• Formal Usability Test: Using a stable product, an animated prototype, or even a paper prototype, test a reasonably large number of subjects against a controlled variety of scenarios. See How Many Subjects Do I Need for a Statistically Valid Survey by Daryle Gardner-Bonneau for pointers on how to decide when you have enough subjects.)


• Controlled Experiment: A comparison of two products, with careful statistical balancing, etc. This may be the hardest method to do "in the real world" but it’s the one you need to publish the results.


• Questionnaires: formal questionnaire, matching questionnaire (sometimes these are similar to a card-sorting exercise), phone questionnaire. Each of these formats has pluses and minuses, with questionnaire design being a field of its own. See www.stcsig.org/usability/topics/measurement.html for more information on questionnaires.