Social Network Generation

Issues on Social Network Generation for Evaluating Visualizations

Watts and Strogatz first described in (Watts, D. J. and S. H. Strogatz (1998). "Collective dynamics of 'small-world' networks." Nature 393: 440 - 442) the concept of small-world networks. They formalized these networks as graphs with three properties: power-law degree distribution, high clustering coefficient and small average shortest path. In the same paper they propose a basic model fitting these properties consisting in a grid (fixed local neighborhood) with additional links simulating some unexpected relations support to the six degrees of separation discovered by Milgram (Milgram, S. (1967). "The small world problem." Psychology Today: 60-67). Barabási and Albert proposed an incremental model to improve it (Barabási, A.-L. and R. Albert (1999). "Emergence of Scaling in Random Networks." Science 286(5439): 509 - 512. ). Since Watts and Strogatz’ model, several have been proposed each generating networks with one or two of the described properties (power-law) but none combine the three of them.

Here are some results of available generators present in the JUNG package.

Small-World Generator

WattsBetaSmallWorldGenerator

Parameters: numNodes (the number of nodes in the ring lattice), beta (the probability of an edge being rewired randomly; the proportion of randomly rewired edges in a graph) and degree( the number of edges connected to each vertex; the local neighborhood size). Degree must be even.

Parameters and Resulting Graph characteristics

graphs	W1	W2	W3	W4	W5	W6	W7	W8	W9	W10	W11	W12
numNodes	47	47	47	47	47	47	47	47	47	47	47	94
beta	0.1	0.3	0.5	0.7	0.9	0.3	0.3	0.3	0.3	0.7	0.1	0.1
degree	6	6	6	6	6	2	4	8	10	4	8	8
numNodes	47	47	47	47	47	47	47	47	47	47	47	94
numEdges	282	282	282	282	282	94	188	376	470	188	376	752
components	1	1	1	1	1	2	1	1	1	1	1	1
density	0.36	0.36	0.36	0.36	0.36	0.21	0.29	0.41	0.46	0.29	0.41	0.29
clusteringCoefficient	0.51	0.25	0.15	0.09	0.12	0.23	0.25	0.32	0.38	0.07	0.53	0.52
diameter	6	4	4	4	4	-	6	4	3	5	5	6
averageShortestDistance	2.97	2.4	2.32	2.3	2.29	-	3.24	2.15	1.98	2.83	2.56	3.15
minDegree	5	4	4	3	4	1	2	5	8	2	7	6
maxDegree	8	9	9	9	9	4	6	10	13	8	10	10

GraphMl files and Pictures:

• Node-Link diagrams are ordered with the linLog algorithm of Andreas Noack [Graph Drawing 2005] (with edge-repulsion coefficient of 2.5f).
• Matrices are reordered with the TSP-Based algorithm described by Henry and Fekete [Infovis 2006].

W1 SmallWorld_47_0.1_6

W2 SmallWorld_47_0.3_6

W3 SmallWorld_47_0.5_6

W4 SmallWorld_47_0.7_6

W5 SmallWorld_47_0.9_6

W6 SmallWorld_47_0.3_2

W7 SmallWorld_47_0.3_4

W8 SmallWorld_47_0.3_8 (Second matrix not reordered)

W9 SmallWorld_47_0.3_10 (Second matrix not reordered)

W10 SmallWorld_47_0.7_4

W11 SmallWorld_47_0.1_8

W12 SmallWorld_94_0.1_8

KleinbergSmallWorldGenerator

Parameters:latticeSize (the lattice size (length of row or column dimension)) and clusteringExponent (the clustering exponent parameter).

Parameters and Resulting Graph characteristics

graphs	W1	W2	W3	W4	W5	W6	W7	W8	W9	W10	W11
numNodes (sqrt)	7	7	7	7	7	7	7	10	10	10	10
clustering exponent	0.1	0.5	1	2	2.5	4	8	2	4	8	12
numNodes	49	49	49	49	49	49	49	100	100	100	100
numEdges	490	490	490	490	490	490	490	1000	1000	1000	1000
components	1	1	1	1	1	1	1	1	1	1	1
density	0.45	0.45	0.45	0.45	0.45	0.45	0.45	0.32	0.32	0.32	0.32
clusteringCoefficient	0.08	0.09	0.14	0.19	0.19	0.26	0.32	0.18	0.23	0.32	0.33
diameter	4	4	4	4	4	5	5	5	6	7	7
averageShortestDistance	2.38	2.36	2.37	2.44	2.48	2.54	2.73	3.1	3.57	3.65	3.68
minDegree	9	9	9	9	9	9	9	9	9	9	9
maxDegree	14	12	13	12	12	13	12	13	13	14	12

Scale-Free Networks Generator

BarabasiAlbertGenerator

Parameters: init_vertices (number of vertices that the graph should start with), numEdgesToAttach (the number of edges that should be attached from the new vertex to pre-existing vertices at each time step) and numSteps (number of time steps). init_vertices must be superior or equal to numEdgesToAttach.

Parameters and Resulting Graph characteristics

graphs	W1	W2	W3	W4	W5	W6	W7	W8
numStartingNodes	4	4	4	4	2	2	2	4
numAdditionnalEdges	2	2	2	1	1	1	2	4
numSteps	10	50	100	100	100	50	50	50
numNodes	14	53	104	80	76	51	52	54
numEdges	40	200	400	158	150	100	200	400
components	1	1	1	1	1	1	1	1
density	0.45	0.27	0.19	0.16	0.16	0.2	0.27	0.37
clusteringCoefficient	0.15	0.2	0.07	0.51	0.51	0.66	0.16	0.23
diameter	4	6	6	11	14	8	5	4
averageShortestDistance	2.24	2.81	3.18	5.26	5.7	3.74	2.8	2.15
minDegree	2	1	2	1	1	1	2	4
maxDegree	5	16	19	8	12	16	17	26

EppsteinPowerLawGenerator

Parameters: numVertices (the number of vertices for the generated graph), numEdges (the number of edges the generated graph will have, should be Theta(numVertices)) and r (the model parameter).

Issues on using real Social Networks for Evaluating Visualizations

Here is a panel of undirected networks.

Parameters and Resulting Graph characteristics

Name	Infovis Comp4
Type	Co-authoring network
File
numNodes	32
numEdges	109
components	1
density	0.33
clusteringCoefficient	0.81
diameter	6
averageShortestDistance	2.60
minDegree
maxDegree