Geography Reference
In-Depth Information
In statistics, the result is called statistically significant when it is unlikely to have occurred
by chance alone, according to a pre-determined threshold probability, the significance level.
Critical tests of this kind may be called tests of significance. When such tests are available,
we can say whether the second sample is/ is not significantly different from the first one
[44].
From a more detailed evaluation of different types of basic eye movements (fixations and
saccades), or gaze data metrics such as dwell time, it is possible to deduce a series of
numeral metrics suitable for other statistical testing.
Different composition perception with two different groups of map users (experienced
cartographers and non-cartographers) was verified by the testing of measured results by a
two sample t-test, which is a method of mathematical statistics making possible to verify the
null hypothesis that the means of two normally distributed populations are equal.
Differences of the mean dwell time of two groups of users were tested on particular Areas of
Interest of the map list - title of the map, the map, the legend, the imprint and secondary
maps. A zero hypothesis H0 was tested: mean values of particular choices are the same.
Concrete results are illustrated in table 1.
mean of
carto [ms]
mean of non-
carto [ms]
t
df
p-value
alpha
statement
Main map
-2,2189
33,374
0,0334
0,05
2375,58
3080,11
Rejecting H0
Map
heading
3,7546
51,501
0,0004
0,05
631,27
230,78
Rejecting H0
Additive
map 2
0,0963
36,715
0,9238
0,05
387,84
376,47
Fail to reject H0
Additive
map 1
-0,1874
40,321
0,8523
0,05
260,59
284,08
Fail to reject H0
Masthead
1,1999
36,275
0,2380
0,05
127,27
57,57
Fail to reject H0
Map
legend
0,2211
45,702
0,8260
0,05
99,50
84,33
Fail to reject H0
Table 1.
Results of two sample t - test of dwell time on particular compositional map elements of two
different user groups.
By comparing the mean dwell time in particular AOI it is evident that both groups spent
most time on the main map field. Extremely long time was noticed at students of
cartography in AOI covering the map title. The same AOI was on the 4
th
position with non-
cartographers.
The t-test result disproved the zero-hypothesis saying that the values of the mean dwell
time were the same with AOI map heading and the main map field. The visit rate of the
main map field was significantly higher with non-cartographers. On the contrary, the map
