Structural cohesion

From Wikipedia, the free encyclopedia

It has been suggested that Perceived Cohesion Scale be merged into this article or section. (Discuss)

Structural cohesion is the sociological and graph theory conception ^[1][2] and measurement of cohesion for maximal social group or graphical boundaries where related elements cannot be disconnected except by removal of a certain minimal number of other nodes. The solution to the boundary problem for structural cohesion is found by the vertex-cut version of Menger's theorem. The boundaries of structural endogamy are a special case of structural cohesion. It is also useful to know that k-cohesive graphs (or k-components) are always a subgraph of a k-core, although a k-core is not always k-cohesive. A k-core is simply a subgraph in which all nodes have at least k neighbors but it need not even be connected.

Contents 1 Software 2 Examples 3 See also 4 References

[edit] Software

Cohesive.blocking is the R program for computing structural cohesion according to the Moody-White (2003) algorithm. This wiki site provides numerous examples and a tutorial for use with R.

[edit] Examples

Some illustrative examples are presented in the gallery below:

The 6-node ring in the graph has connectivity-2 or a level 2 of structural cohesion because the removal of two nodes is needed to disconnect it.

The 6-node component (1-connected) has an embedded 2-component, nodes 1-5

A 6-node clique is a 5-component, structural cohesion 5

[edit] See also

• Community cohesion
• Social cohesion
• Social network
• Social-circles network model
• Perceived cohesion

[edit] References

1. ^ Moody, James; White, Douglas (2003). "Structural Cohesion and Embeddedness: A Hierarchical Concept of Social Groups." (PDF). American Sociological Review 68 (1): 1–25. http://www2.asanet.org/journals/ASRFeb03MoodyWhite.pdf. Retrieved on 2006-08-19. 
2. ^ White, Douglas; Frank Harary (2001). "The Cohesiveness of Blocks in Social Networks: Node Connectivity and Conditional Density." (book). Sociological Methodology 2001 (Blackwell Publishers, Inc., Boston, USA and Oxford, UK.) 31 (1): 305–359. doi:10.1111/0081-1750.00098. http://www.ingentaconnect.com/content/bpl/some/2001/00000031/00000001/art00098;jsessionid=1f96pkuejdhry.victoria. Retrieved on 2006-08-19.