Information Technology Reference
In-Depth Information
Discoverability
mobile phone, the phone gives an audio cue when
the tag is detected. However, the user should
already know that the tag would be available for
use somewhere.
In the information tag trial, users discovered
tags that did not respond to touch. For example,
the tags used for parking payment could be used
only by subscribers who had the parking payment
Java application installed in their mobile phone.
The users found these situations very annoying.
Therefore, it could be recommended that standard-
ized markings would not be used on tags that are
not targeted for all users. In these cases, the users
of a special-purpose application should learn to
find the service tags by other means.
We used the same sizing in each trial, i.e. the
size of the visual marking was always the same
as the size of the tag (c. four centimetres). This
seemed to be adequate when the tags were located
near the user, i.e. within reach. However, several
users complained that the visual markers were too
small when the tags were located further away. This
was especially noted in the theatre pilot, where
the smart posters were placed on the walls of the
theatre building. The size of the visual icon was
obviously too small to be properly seen from a
distance, as is illustrated by the following com-
ments made by the theatre visitors:
The tags can provide support for service discov-
ery only when the user is able to discover the
tags embedded in things and the environment.
Therefore, the tags must be marked somehow,
or the user must know where the tag is. In small,
specific purpose applications, it can be reason-
able or even desirable to have hidden tags that
are known only by the users to whom they are
targeted (e.g. service described in Häikiö et al.,
2007). However, for services that are targeted for
larger audiences or random users, marking the
tag somehow is crucial.
In small-scale prototypes of information tags,
we have used special-purpose visual design for
each tag. For example, to access bus time sched-
ules we used an icon representing a bus to mark
the tag. However, we quickly found out that when
there were many services available, the users had
trouble discovering tags that did not share com-
mon visual characteristics. In the trials presented
here, we used a special icon to mark the tag, and
then explained the content provided on the space
around the tag. In the first trials, we used the icon
illustrated in Figure 1 (similar to work presented
by Arnall (2006)). The users learned quickly that
the round icon was always used to mark a tag.
However, soon after, the NFC Forum (http://www.
nfc-forum.org) introduced their own standardized
visual icon that is illustrated in Figures 2 and 3.
We decided to adopt the standardized icon, as
standardization seemed to be a good way for in-
troducing a common language to large audiences
globally. Amazing NFC trial users reported having
experienced no difficulties in locating the NFC
tags at the control points: 92.6% of the pupils
stated that finding tags was easy.
As the markings we used were based on visual
icons, for the visually impaired, discovering tags
can be problematic. With NFC technology, it is,
however, possible to implement an audio ap-
plication that can aid in locating a tag. When the
visually impaired user brushes a surface with a
“The target marks used in the posters should
be printed larger so that one could see it over a
distance.”
“The tags were too small.” (translated by the
authors)
On the other hand, if the visual icon used to
mark the placement of the tag is larger than the tag
itself, the users might face difficulties in finding
the correct spot to touch within the visual icon.
This could be solved, for example, by having
additional visual signals inside the visual icon to
indicate the optimum spot to touch.
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