<P> Setting up a usability test involves carefully creating a scenario, or realistic situation, wherein the person performs a list of tasks using the product being tested while observers watch and take notes (dynamic verification). Several other test instruments such as scripted instructions, paper prototypes, and pre - and post-test questionnaires are also used to gather feedback on the product being tested (static verification). For example, to test the attachment function of an e-mail program, a scenario would describe a situation where a person needs to send an e-mail attachment, and ask him or her to undertake this task . The aim is to observe how people function in a realistic manner, so that developers can see problem areas, and what people like . Techniques popularly used to gather data during a usability test include think aloud protocol, co-discovery learning and eye tracking . </P> <P> Hallway testing is a quick and cheap method of usability testing in which randomly - selected people--e.g., those passing by in the hallway--are asked to try using the product or service . This can help designers identify "brick walls", problems so serious that users simply cannot advance, in the early stages of a new design . Anyone but project designers and engineers can be used (they tend to act as "expert reviewers" because they are too close to the project). </P> <P> In a scenario where usability evaluators, developers and prospective users are located in different countries and time zones, conducting a traditional lab usability evaluation creates challenges both from the cost and logistical perspectives . These concerns led to research on remote usability evaluation, with the user and the evaluators separated over space and time . Remote testing, which facilitates evaluations being done in the context of the user's other tasks and technology, can be either synchronous or asynchronous . The former involves real time one - on - one communication between the evaluator and the user, while the latter involves the evaluator and user working separately . Numerous tools are available to address the needs of both these approaches . </P> <P> Synchronous usability testing methodologies involve video conferencing or employ remote application sharing tools such as WebEx . WebEx and GoToMeeting are the most commonly used technologies to conduct a synchronous remote usability test . However, synchronous remote testing may lack the immediacy and sense of "presence" desired to support a collaborative testing process . Moreover, managing inter-personal dynamics across cultural and linguistic barriers may require approaches sensitive to the cultures involved . Other disadvantages include having reduced control over the testing environment and the distractions and interruptions experienced by the participants' in their native environment . One of the newer methods developed for conducting a synchronous remote usability test is by using virtual worlds . </P>

What would be some of the circumstances for testing a live system