| Literature DB >> 26503113 |
B J Kreakie1, K C Hychka2, J A Belaire3, E Minor4, H A Walker2.
Abstract
Social network analysis (SNA) is based on a conceptual network representation of social interactions and is an invaluable tool for conservation professionals to increase collaboration, improve information flow, and increase efficiency. We present two approaches to constructing internet-based social networks, and use an existing traditional (survey-based) case study to illustrate in a familiar context the deviations in methods and results. Internet-based approaches to SNA offer a means to overcome institutional hurdles to conducting survey-based SNA, provide unique insight into an institution's web presences, allow for easy snowballing (iterative process that incorporates new nodes in the network), and afford monitoring of social networks through time. The internet-based approaches differ in link definition: hyperlink is based on links on a website that redirect to a different website and relatedness links are based on a Google's "relatedness" operator that identifies pages "similar" to a URL. All networks were initiated with the same start nodes [members of a conservation alliance for the Calumet region around Chicago (n = 130)], but the resulting networks vary drastically from one another. Interpretation of the resulting networks is highly contingent upon how the links were defined.Entities:
Keywords: Cybermetrics; Hyperlink; Relatedness; Social network analysis; Stakeholder
Mesh:
Year: 2015 PMID: 26503113 PMCID: PMC4712246 DOI: 10.1007/s00267-015-0624-8
Source DB: PubMed Journal: Environ Manage ISSN: 0364-152X Impact factor: 3.266
Definitions of relevant social network terms
| Term | Definition | Reference |
|---|---|---|
| Node | Fundamental unit of a network. For our research, this unit is typically an organization or may also be thought of as a website | Newman ( |
| Start nodes | List of nodes selected a priori from which the networks were built based on link definitions described below. All networks created were initialized with the same start nodes. However, the final nodes will differ based on researchers’ rules for growing the network or node snowballing | Newman ( |
| Link | Links or connections between nodes. The networks in this research were created by varying the way in which links are defined: hyperlink, relatedness, survey-based (traditional), or combined approaches | Newman ( |
| Hyperlink network | Network constructed by following electronic links provided on the start node websites that automatically move the browser to a new web address | Defined by the work presented here |
| Relatedness network | Network constructed by identifying websites related websites to the start nodes based on a measure of the similarity between two websites derived from a proprietary algorithm developed by Google | Google Support ( |
| Traditional network | Network constructed by surveying start nodes. Starts nodes are asked to identify missing nodes and their links in the network. Depending on the methods, nodes may be snowballed into the network and also asked to complete survey | Belaire et al. ( |
| Combined network | Network constructed by merging all unique nodes and links from the hyperlink and relatedness networks | Defined by the work presented here |
| Focal network | Reduced network comprised only of nodes with degree greater than or equal to two. Each method of network construction has a corresponding focal network | Defined by the work presented here |
| Metrics | ||
| Average degree | Average number of links per node | Belaire et al. ( |
| Average path length | Average number of steps between any two nodes in a network | Vance-Borland and Holley ( |
| Betweenness | How much each node contributes to minimizing the distance between nodes in the network; variation in the number of times nodes lie on the path between two other nodes (1 indicates all links pass through a single node) | Vance-Borland and Holley ( |
| Diameter | Maximum number of steps between any two nodes in the network | Vance-Borland and Holley ( |
| Link density | Number of links divided by the number of possible links (ranges from 0 to 1) | Belaire et al. ( |
| Modularity | How divided the network is based on predefined communities; in this case, we used walk trap (based on random walks) and link betweenness (prunes out links with highest betweenness to leave the portions of the network they connect) to define communities | Newman and Girvan ( |
| Reciprocity | Proportion of links that are bi-directional (claimed by both organizations) | Vance-Borland and Holley ( |
Fig. 1Network diagrams including only nodes with a total degree of two or higher. The nodes are color-coded according to organization type. The size of the node is scaled to its in-degree. a Traditional focal network: based on social survey link definition (results of Belaire et al. 2011). b Hyperlink focal network: based on hyperlink definition. c Relatedness focal network: based on Google’s relatedness link definition. d Combined focal network: network developed from using the results of both the hyperlink and relatedness networks
Summary of network characteristics
| Combined | Hyperlink | Relatedness | Traditional | |
|---|---|---|---|---|
| Base | ||||
| Number of nodes | 287 | 165 | 173 | 127 |
| Number of links | 915 | 524 | 384 | 2636 |
| Diameter | 12 | 6 | 8 | 4 |
| Average degree | 3.19 | 3.18 | 2.22 | 20.76 |
| Link density | 0.01 | 0.02 | 0.01 | 0.16 |
| Reciprocity | 0.07 | 0.03 | 0.09 | 0.46 |
| Average path length | 4.40 | 2.34 | 3.24 | 1.83 |
| Modularity | 0.34 | 0.31 | 0.61 | 0.11 |
| Fully snowballed | ||||
| Number of nodes | 661 | 230 | 337 | – |
| Number of links | 2318 | 712 | 1116 | – |
| Diameter | 11 | 6 | 14 | – |
| Average degree | 3.51 | 3.1 | 3.31 | – |
| Link density | 0.01 | 0.01 | 0.01 | – |
| Reciprocity | 0.16 | 0.04 | 0.29 | – |
| Average path length | 4.69 | 2.44 | 5.06 | – |
| Modularity | 0.46 | 0.37 | 0.62 | – |
The top portion presents the metrics for the base networks (before snowballing), while the bottom proportion presents the metrics after all snowballing was completed
Summary of node distribution across type of organizations
| Combined | Hyperlink | Relatedness | Traditional | |||
|---|---|---|---|---|---|---|
| Focal | Focal | Focal | Focal | Full | ||
| Number of nodes | 661 | 230 | 337 | 127 | 153 | |
| Number of links | 2318 | 712 | 1116 | 2636 | 4140 | |
| Proportion of nodes | ||||||
| Advocacy | 0.31 | 0.36 | 0.23 | 0.38 | 0.39 | |
| College | 0.10 | 0.10 | 0.16 | 0.13 | 0.15 | |
| Commercial | 0.20 | 0.13 | 0.20 | 0.16 | 0.15 | |
| Museum/library | 0.03 | 0.03 | 0.03 | 0.02 | 0.02 | |
| Industry | 0.00 | 0.01 | 0.01 | 0.03 | 0.04 | |
| Information | 0.11 | 0.09 | 0.12 | 0.01 | 0.01 | |
| K-12 | 0.00 | 0.00 | 0.01 | 0.01 | 0.01 | |
| Local government | 0.14 | 0.13 | 0.11 | 0.14 | 0.14 | |
| State government | 0.05 | 0.04 | 0.08 | 0.05 | 0.05 | |
| Federal government | 0.06 | 0.11 | 0.07 | 0.06 | 0.05 | |
Fig. 2Plot of cumulative frequency of degree for each focal network (note log scale)
Fig. 3Plot of percent of start nodes used to initialize the network and the percent of the full network obtained after following snowballing procedures. The shaded cloud represents the standard deviation of the results for each sampled percentage