Geography Reference
In-Depth Information
maximum values for each stimuli, the colour ramp proposed in Fig.
2b
is applied on
the grids and the corresponding maps can as such be compared. These results are
depicted in Fig.
2b
. This visualisation corresponds to the distribution of the
participants
'
dwell times on the map image.
Discussion
The obtained data was analysed descriptively, statistically and visually for several
components to detect how efficient and effective a user can perform a certain task
related on map use. Does the medium on which the maps are displayed have an
influence on the user
s cognitive processes? First, the search times, the needed time
to find the three names in the map image, show no significant difference between
the two mediums. Moreover, no trends could be detected in the graphs that
visualised the mean search times and associated deviations for each stimulus.
This indicates that the digital medium is not more or less efficient when a user
has to search for a points of interest (indicated by their label) on it.
Second, the mean fixation count (number of fixations per second) was analysed
for the two mediums. This mean is closely related to the durations of the fixations
which may indicate the degree of difficulty experienced by the user when
interpreting a certain visual content (e.g. Duchowski
2007
; Holmqvist
et al.
2011
). Longer fixations or a lower fixation count can signify that the user
struggles with interpreting the visual input and needs more time to process the
information. This is closely linked with a higher cognitive load (Harrower
2007
). It
can also indicate that the user considers the visual input more interesting, however,
this explanation can be omitted since in this study only topographic maps with the
same visual qualities were applied and it could thus be assumed that the users look
at all the stimuli with the same level of interest (Ooms et al.
2012
,
2014
). The
fixation count also depends on the length of the saccades: the shorter the saccades,
the higher the fixation count. Table
5
clearly shows that the digital stimuli are linked
with more fixations per second than the paper stimuli. The statistical t-test
established the difference is very high significant. This result can indicate that the
digital maps were less difficult to read and thus interpret than the paper maps. It
could thus be derived that the lower resolution of the screen (digital maps) is likely
to have no negative influence on the user
'
s visual behaviour.
Third and last, the fixation duration was calculated. In contrast to the fixation
count, the differences in mean fixation duration for the two mediums are, accord-
ingly the statistical t-test, not significantly different for paper en digital stimuli.
From this we can conclude that none of the mediums is easier to interpret than the
other. When linking this result to this of the fixations counts, it can be concluded
that the users used shorter saccades to study the digital map
'
s content: the distance
'
between subsequent fixations is shorter.
The distribution of these eye movement metrics is visualised in a grid of Areas of
Interests (AOIs): their count and total duration (or dwell time). The applied colour
