Logo der Fakultät Logo LG Theoretische Informatik

Experimental Analysis of the Accessibility
of Drawings with Few Segments

Philipp Kindermann Wouter Meulemans André Schulz
http://tutte.fernuni-hagen.de/userstudy

Visual Complexity

Number of geometric objects
Edges: 21
Segments: 21
Why?
1. Aesthetic
2. Path Finding
Two graph classes:
sparse graphs and trees

Sparse Graphs Algorithms

ForceDirected
[Fruchterman & Reingold '81]
Well separated vertices Adjacent vertices close
ForceDirFewSeg

Like ForceDirected... But we can straighten paths

Tree Algorithms

Tidier
[Reingold & Tilford '81], [Walker II '90]
Quad
[Rusu et al. '08]
FewSeg [Hültenschmidt et al. '17]
Parallel levels Parent centered
Specified angular resolution Evenly spread out children
Heavy path decomposition
Min. number of segments
Heuristic area reduction

Task: Aesthetics

Task: Path Finding

Task: Furthest Pair

Hypotheses

ForceDirected
ForceDirFewSeg
H1: Path Finding
ForceDirFewSeg > ForceDirected
H2: Aesthetics
ForceDirected > ForceDirFewSeg
H3: Furthest Pair
FewSeg > Tidier > Quad
H4: Aesthetics
Math/CS:
Other:
Tidier > FewSeg > Quad
FewSeg > Tidier > Quad
Tidier
Quad
FewSeg

Stimuli

Sparse Graphs Trees
Layout ForceDirected ForceDirFewSeg Tidier Quad FewSeg
Type ROME Random Balanced Deep Wide
Size 20 nodes 40 nodes 20 nodes 40 nodes
Task Shortest Path Aesthetics Furthest Pair Aesthetics
Rep. 2 Rep. 4 Rep. 2 Rep. 4 Rep.
Tasks
Users 42 21 21
92 tasks in total: split into three groups
84 users: distribute evenly among groups

Results

H1: Path Finding
ForceDirFewSeg > ForceDirected
50% 25% 0% Error Rate - 656 responses
ForceDirFewSeg
ForceDirected
20s 10s 0s Response Time - 656 responses

Results

H2: Aesthetics
ForceDirected > ForceDirFewSeg
1 0.5 0 Preference - 656 responses
ForceDirFewSeg
ForceDirected

Results

H3: Furthest Pair
FewSeg > Tidier > Quad
50% 25% 0% Error Rate - 756 responses
FewSeg
Tidier
Quad
= :p > 0.05
≤ :p < 0.05
< :p < 0.01
≪ :p < 0.001
20s 10s 0s Response Time - 756 responses

Results

H4: Aesthetics
Math/CS:
Other:
Tidier > FewSeg > Quad
FewSeg > Tidier > Quad
1 0.5 0 Preference - 504 responses
FewSeg
Tidier
Quad
Follow-up study:
576 extra responses

Conclusion

ForceDirected
ForceDirFewSeg
H1: Path Finding
ForceDirected > ForceDirFewSeg
(except random large)
H2: Aesthetics
ForceDirected ≥ ForceDirFewSeg
H3: Furthest Pair
Tidier ≥ FewSeg > Quad
H4: Aesthetics
Math/CS:
Other:
Tidier > FewSeg > Quad
FewSeg > Tidier > Quad
Tidier
Quad
FewSeg