Word: Moderated usability testing 

Definition: A moderator asks questions, instructs and directs a participant through a set of tasks while ensuring that the respondent is guided in such a manner that the goals of the study are accomplished.

Thought: In a moderated usability test the moderator has specific tasks for the participant to complete and she will  track these questions herself alongside the participant. The plus sides of this method is that it can can be more engaging than unmoderated testing and it leaves room for the moderator to ask followup questions and observe subtle body language clues. It is also a preferable method if the design test is complex in nature or the prototype is rough or in early stages. This way the moderator can provide advanced guidance and instruction.

In my opinion the best resource to get you started on moderated usability testing, bar none, is Steve Krug's book "Rocket Surgery Made Easy: The Do-It-Yourself Guide to Finding and Fixing Usability Problems." If you have not read this book then stop reading this post right now and go do it! Seriously... do it!

On the flip side, moderated usability testing requires time and coordination. These types of tests also prove more difficult to recruit participants. It is important to remember that data could be effected by the mere presence of a moderator as well.

Question: In what types of situations have you found moderated usability testing to most effective?