SOLVING GEOSPATIAL TASKS IN 2D AND 3D VISUALIZATIONS OF MAPS - Information Visualisation: Techniques, Usability and Evaluation - page 246

capabilities as low, whereas n 2 =6 rated them as high. Fig. 12.10 shows
boxplots for accuracy (a) and times (b) in both groups.
The group stating high confidence in its 3D vision capabilities
achieved clearly better accuracy both in the 2D visualization and in the 3D
visualization (Fig. 12.10(a)). This difference in accuracy was significant in
2D (t=2.172, df=31.049, p-value=0.03761), as well as in 3D (t=2.4045,
df=33.27, p-value=0.02192). The same is true for times, whereby the
confident group showed shorter response times (Fig. 12.10(b)). This
difference in time was, however, only significant in the 2D visualization
condition (n 1 =12, n 2 =6, W=77, p-value=0.0241).

(a) (b)

Fig. 12.10. Results for groups rating their 3D/spatial capability as low and high.
Accuracies (a) and times (b) are presented separately for both visualization
conditions.

Visual discomfort

Eye strain and associated dizziness/headache are factors in studies of 3D
visualizations. Here, n 1 =8 subjects, or 44%, reported visual discomfort.
N 2 =10 subjects did not. A comparison of accuracy and times in the 3D
visualization is shown in Fig. 12.11(a) and (b). There were no statistically
significant differences between the groups, but it is notable that the group
with visual discomfort performed better. The means of accuracy for this

x

Discomfort

group ( =0.602) and the group without visual discomfort