A lab that should be set up “on the go” at different places must, based on our experience, at least fulfill the following requirements:
Least intrusive: The lab should not contain any unnatural or unexpected equipment such as huge suitcases for equipment or lots of wiring through the room. The use of consumer equipment known by the typical participant is recommended (such as e.g. laptop computers, camcorders, tripods etc.)
As little equipment as possible: Each piece of equipment
needs to be stowed away somewhere (number and size of bags, etc),
needs to be carried (weight to carry, want to be cabin luggage in airplane, etc),
needs to be set up (time and intrusiveness for the participants),
needs a power supply (enough supplies available at the current location?),
needs to be connected to other devices (cables through the room, possible accidents with human injuries and equipment damage etc.),
needs to be controlled by the moderator (the more equipment the moreproblems may arise and the more attention the moderator needs to spend on the equipment versus the test situation)
might frighten the participant and feel insecure (“I am being tested /observed!”)
could be stolen, get lost or damaged (which might disable the whole system)
Low time to set up: A mobile lab is called “mobile” because it needs to be set up quickly at different locations. E.g. in case of use in a typical company office environment there is no time for long lasting set ups with putting cables through the room connecting lots of devices to each other and to power supply (in that point of view the use of video mixers and audio mixers is unwanted and too complicated)
Low time to tear down: If an onsite test has been finished (e.g. at a consumers home), you typically don’t want to take a long time to disassemble all equipment and stow it away properly. Maybe you have to catch the next plane or need to go to another participant.
Post analysis: Using a mobile lab also means that most of the coding and analysis has to be done offline in your office, after the test recording. During the test there is little time for making complex annotations or coding, based on the fact that lots of things happen simultaneously, which need your attention and are very difficult to track quickly and properly (e.g. making a note while the user switches a task and something interesting happens at the same time)
