Wireless Sensor and Actuator Networks for Lighting Energy ...

the research and the commercial systems in this experiment automatically maintained
the desktop illuminance at the participants’ preferences, and the participants were asked
to comment on whether or not they noticed the difference between the two systems.
8.4.2 Testing Procedure
Subjects were offered a brief explanation of how the automatic lighting system
works in general and how it can be overridden with both methods of control. The
participants were only told that two types of overriding mechanisms were to be tested
without the knowledge that the lighting systems were actually different. Before the test
began, participants were able to play with the controllers to gain familiarity with their
operation. Each participant received a questionnaire as attached in Appendix B.7, and
was invited to answer or disregard any of the questions and write down any comments
or complaints that come to mind during the test. In order to simulate a real office
working condition, the participants were encouraged to bring their own work to the test,
preferably a mixture of paper- and computer-based tasks. An artificial task would be
provided should the participant fail to find a suitable task to bring in. Subjects might
work with either their own laptop or the desktop PC on the experiment worksurface that
run the research system; however, they could only override the research system with the
GUI provided by the desktop PC no matter which computer they chose to work on their
own tasks.
In order to avoid any possible bias caused by the order of the systems to which
the subjects were exposed, half of the participants started with the research system
while the other half started with the commercial system. Furthermore, the investigator
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