Geography Reference
In-Depth Information
Table 2 Wilcoxon test of differences for 2D and 3D maps for whole dataset
Metric
Alpha
W
p-value
Statement
Trial duration
0.05
49,054.5
0.3591
Failed to reject
Time to answer
0.05
48,686.5
0.2826
Failed to reject
Fixation count
0.05
48,965
0.3387
Failed to reject
Fix. duration med.
0.05
47,549.5
0.1183
Failed to reject
Scanpath length
0.05
114,566
0.8873
Failed to reject
Apart from the analyses for particular maps; also the whole dataset for all maps
was analysed (see Table
2
). It was found that results for map 9 influenced all results.
If the map 9 was included in the dataset, statistically significant differences were
found for Time to Answer and Fixation Duration Median. The values were higher
for the 3D map. When the map 9 data were omitted, with the Wilcoxon rank sum
test on the significance level
0.05, no differences between 2D and 3D variant
were found for any of the metrics.
Statistical analysis showed that there are statistically significant differences in
eye-tracking metrics between 2D and 3D variant of a particular map, but the results
did not indicate that one of the variants is better than the other. Within the analysis
of the entire dataset as a sum of all maps, no statistically significant differences
were found for any of the studied eye-tracking metric.
α
¼
Visual Analytics of Data
Visual analytics, the science of analytical reasoning facilitated by interactive visual
interfaces is an important tool for investigation of a large amount of data. For the
visual analytics of recorded eye-tracking data, software CommonGIS developed at
the Fraunhofer Institute IAIS was used. For data conversion from BeGaze software
to CommonGIS environment, the conversion tool created by Kristien Ooms was
used. Fixations from BeGaze software were transformed into the trajectories, which
are represented as lines in CommonGIS.
For data analyses, two methods introduced by Andrienko et al. (
2012
) were used.
First method, Flow Map, represent results of discrete spatial and spatio-temporal
aggregation of trajectories. Arrows represent multiple movement of gaze from one
location to another. The thickness of arrows is derived from variable Number of
moves between defined voronoi polygons. Only arrows representing more than
three moves are displayed.
Second used method is Temporal View of Trajectories. The horizontal dimen-
sion of the graph represents time, and the colour of the lines displays the distance
between current gaze position and the target in pixels.
In Fig.
3
, three map pairs are shown. First image from the top shows the
situation, when more of cumulative gaze trajectories were observed in case of 3D
variant of the map (right part of the image). The Temporal View shows that
