# Two-mode networks Kaibin He.

## Presentation on theme: "Two-mode networks Kaibin He."— Presentation transcript:

Two-mode networks Kaibin He

Outline Data structure Visualization Quantitative Analysis
Qualitative Analysis

Rectangular data array
1 2 3 A B 1 2 3 A B

Two-mode to One-mode Data>Affiliations Cross-product(binary data) : multiplies each of A's scores by the corresponding score for B, and then sums across the columns A B 1 2 3 1 2 3 A B 1 2 3

Two-mode to One-mode Minimums (valued data): examines the entries of A and B for campaign 1, and selects the lowest score (zero). It then does this for the other campaigns and sums. A B 1 2 3 1 2 3 A B 1 2 3

Bipartite The matrix is formed by adding the rows as additional columns, and columns as additional rows. Transform>Bipartite A B 1 2 3 1 2 3 A B

Visualization Netdraw>File>UCINET dataset>2-Mode Network
Use scaling method to locate the points Example: Zhou, Yuan, Wang (2013)

Quantitative analysis
Identify underlying dimensions of the joint space of actor-by-event. Two-mode SVD analysis. (valued data)Tools>Scaling/Decomposition>SVD Two-mode factor analysis. (valued data)Tools>Scaling/Decomposition>Factor Analysis Two-mode correspondence analysis. (binary data)Tools>Scaling/Decomposition>Correspondence

SVD Singular Values RCScores Row Scores Column Scores Scatter Plot
Example

Correspondence analysis
Row/Column Scores Scatter plot Example

Qualitative analysis Block models Two-mode core-periphery analysis.
Network>2-Mode>Categorical Core>Periphery Two-mode factions analysis Network>2-Mode>2-Mode Factions

Two-mode core-periphery analysis
The "core" is a cluster of frequently co-occurring actors and events. The "periphery" consists of a partition of actors who are not co-incident to the same events. 0 means bad fit, 1 means excellent fit. Ideal density matrix 1 2

Two-mode factions analysis
Factions are groupings that have high density within the group, and low density of ties between groups. Example

Recommended paper The Quest for Content: How User-Generated
Links Can Facilitate Online Exploration JACOB GOLDENBERG, GAL OESTREICHER-SINGER, and SHACHAR REICHMAN JMR, 2012

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