Geography Reference
In-Depth Information
Table 3 Selected data: participants and stimuli
Part.
1D
2P
3D
4P
5D
6P
Part.
1P
2D
3P
4D
5P
6D
P01
x
x
x
x
x
x
P10
x
x
x
x
x
P05
x
x
x
x
x
x
P14
x
x
x
x
x
P07
x
x
x
x
P16
x
x
x
x
x
x
P09
x
x
x
x
x
x
P18
x
x
x
x
x
x
P11
x
x
x
x
x
x
P20
x
x
x
x
x
x
P13
x
x
x
x
x
x
P22
x
x
x
x
P15
x
x
x
x
x
x
P24
x
x
x
x
x
x
P17
x
x
x
x
x
x
P28
x
x
x
x
x
P21
x
x
x
x
x
P30
x
x
x
x
x
x
P25
x
x
x
x
x
x
P32
x
x
x
x
x
P27
x
x
x
x
P34
x
x
x
x
x
x
P29
x
x
x
x
x
x
P36
x
x
x
x
x
x
P33
x
x
x
x
x
TOT.
13
11
12
12
12
12
TOT.
10
10
11
11
12
12
The recordings that have been selected are listed in Table
3
. The recordings of
some participants have been removed completely, whereas for other participants
the recordings of a limited number of trials was considered unacceptable. From this
table it can be derived that, after selection, a sample size of at least 10 individuals is
still available for each stimulus.
Creating the Gridded Visualisation
The registered data will be visualised in a grid AOIs. The method has already been
used by Brodersen et al. (
2001
) and Ooms et al. (
2014
). Since the aim of the paper is
to study the users
attentive behaviour, only the fixations will be considered. The
number of fixations on a specific location might indicate where interesting elements
are located. The duration of the fixations can indicate whether the participants find
it difficult to interpret the visual content (at a certain location) (e.g. Duchowski
2007
; Holmqvist et al.
2011
).
Heatmaps (which are actually density maps) are often used to visualise the
distribution of the fixation densities of a certain participant across the stimuli
(Spakov and Miniotas
2007
). Typically, a green-yellow-red colour ramp is used,
although this is not cartographically correct (e.g. Bertin
1967
). In OGAMA it is
possible to adapt this colour ramp, and use only one hue (which is more suitable).
However, it is not possible to compare the different heatmaps objectively as the
colour ramp is calculated separately (and thus differently) for each stimulus. For
example, the maximal total fixation duration (or dwell time) is 11,595 ms for the
paper version of
'
and 9,194 ms for its digital version. The same colour
ramp (0-100 %) will be applied to both stimuli. Consequently, the same colour
Assesse
'
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