Information Technology Reference
In-Depth Information
It was considered very helpful to have the same interaction device for printed
and digital documents.
17
Participants reported that this made the interaction faster
and connected printed and digital documents more directly. In the interviews, 14
participants valued that they did not have to switch between different devices for
paper and for the computer screen. One participant emphasized on the fact that
using the same pen for creating a hyperlink between paper and digital documents is
helpful, as it gives the feeling of connecting documents more directly.
Pen-enabled Display
When comparing the pen-enabled tabletop display with the
pen-enabled vertical screen, the tabletop configuration was clearly preferred. While
four participants reported in the interviews to prefer a vertical screen because it
is easier to read and printed documents cannot cover parts of the display, ten par-
ticipants preferred a horizontal tabletop configuration. This is inline with the find-
ings which Morris et al. reported on active reading with different display config-
urations [99]. Most important reasons mentioned in the interviews were first that
it is more natural and ergonomic to use a pen on a horizontal surface and second
that printed and digital documents are more closely coupled using one surface for
both of them. However, three participants perceived an extra effort for rearranging
documents on the display. This discomfort is due to two deficiencies of our current
prototype: the space provided on the tabletop is limited and no provision is made
for coping with occlusions of displayed pages.
A further problem of the current tabletop prototype is the image quality of the
display. While this is comparable or even superior to the quality of other tabletop
displays, is does not yet reach the quality of standard screens. While this is not prob-
lematic in many application areas of tabletop displays, text has high requirements
concerning display quality. Both contrast and luminance of our current prototype are
acceptable for using the display for some hours but must be improved if the display
shall be used on a regular basis.
When asked about the convenience of using the pen on the screen, the partici-
pants who had used the screen in a tabletop configuration reported a better score
18
than those of the vertical display condition
19
. While this difference is not signifi-
cant, it is in line with our observations that it was more difficult for the participants
to use the pen on the vertical display.
Performance Gain
As depicted in Fig. 6.13, completing the information answer-
ing task with CoScribe took in average only about 60 % of the time that was needed
in the control setting. This difference is highly significant
20
and confirms our hy-
pothesis H1. As the two document collections did not result in significantly different
completion times, we analyzed them together.
Figure 6.14 gives the completion times for the individual questions. This shows
that all questions have been solved more quickly using CoScribe except for the
17
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