Carlos Manuel Rodrigues Machado Autonomic Ubiquitous Computing

In this WC, the light operation was setup in a different way and in a non- standard way.
Before the installation of the system, it was noticed that the WC lights tend to be used at the same
time as in almost all WC usages. This situation was not acceptable in terms of power saving,
because the mirror light tends to obfuscate the light produced by the low-power main light bulb. In
order to avoid this situation and to get some energy saving, the system was setup not to allow the
two light points to be activated at the same time. The setup, in the Teleswitch device, was defined
to switch-off any lights in an exclusive way, i.e., when activating a light point, the other is turned-off
at the same time.
The setup of the WC light in a non-standard way has immediately started to be noticeable by
the users due to their strange behaviour. When activating the light, the difference was almost not
perceived by the users, but whenever they tried to turn-off the lights, then the problems got started,
mainly when they mistook the correct switch. When that happened, the other light turned on, the
other turns-off and the user noticed that he has mistaken the switch. Immediately after, the user
corrected the action by pressing the other switch which turned on the original light and turned off
the other one. At this point the user is exactly in the same situation it had started. This sequence
can happen consecutively unless the user concentrates on what is the right switch for the light that
is supposed to be activated. This situation leads to some sort of frustration of the users concerning
the setup of lights.
Nevertheless, as time went by, the users have changed their behaviour to avoid the cycle of
mistaken actions. One of the users reported that he always uses the same light (mirror light), using
therefore the same switch. The other user uses employs the two lights, but when turning off the
light, it executes a rapid switch-on and switch-off in the same switch that results in all lights being
turned off.
The difficulty of the user to turn-off the light in the WC shows that simple changes in the
traditional functionality may have impact on a non-foreseen way.
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