Cited by 2,450Complex Network Analysis TechniquesBioinformatics and Genomic NetworksAdvanced Clustering Algorithms Research

Defining and identifying communities in networks

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Radicchi, Filippo, Castellano, Claudio, Cecconi, Federico, Loreto, Vittorio, Parisi, Domenico·2004·Proceedings of the National Academy of Sciences

Abstract

The investigation of community structures in networks is an important issue in many domains and disciplines. This problem is relevant for social tasks (objective analysis of relationships on the web), biological inquiries (functional studies in metabolic and protein networks), or technological problems (optimization of large infrastructures). Several types of algorithms exist for revealing the community structure in networks, but a general and quantitative definition of community is not implemented in the algorithms, leading to an intrinsic difficulty in the interpretation of the results without any additional nontopological information. In this article we deal with this problem by showing how quantitative definitions of community are implemented in practice in the existing algorithms. In this way the algorithms for the identification of the community structure become fully self-contained. Furthermore, we propose a local algorithm to detect communities which outperforms the existing algorithms with respect to computational cost, keeping the same level of reliability. The algorithm is tested on artificial and real-world graphs. In particular, we show how the algorithm applies to a network of scientific collaborations, which, for its size, cannot be attacked with the usual methods. This type of local algorithm could open the way to applications to large-scale technological and biological systems.

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Authors
Radicchi, F., Castellano, C., Cecconi, F., Loreto, V., & Parisi, D.
Affiliations
University of Rome Tor Vergata (IT)
Corresponding author
Loreto, Vittorio
Venue
Proceedings of the National Academy of Sciences
Published
2004-02-23
Volume
101
Issue
9
Pages
2658-2663
ISSN
  • 0027-8424 (ISSN-L)
  • 1091-6490
OpenAlex
W2038920443
Cited by
2,450
References
31
Citations by year
2026: 36 · 2025: 69 · 2024: 69 · 2023: 97 · 2022: 126 · 2021: 116 · 2020: 133 · 2019: 120 · 2018: 161 · 2017: 141 · 2016: 130 · 2015: 136 · 2014: 186 · 2013: 147 · 2012: 139
FWCI
44.55
Type
journal article
Language
en
Open access
Locations
  • Proceedings of the National Academy of Sciences (publishedVersion)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • arXiv (Cornell University) (submittedVersion)
  • IRIS Research product catalog (Sapienza University of Rome) (submittedVersion)
  • arXiv (Cornell University)
Topics
  • Physical Sciences › Physics and Astronomy › Statistical and Nonlinear Physics › Complex Network Analysis Techniques
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Bioinformatics and Genomic Networks
  • Physical Sciences › Computer Science › Artificial Intelligence › Advanced Clustering Algorithms Research
Keywords
community structure, community detection, computational cost, research collaboration networks, large-scale networks, biological networks, technological networks
MeSH terms
Algorithms, Football, Humans, Metabolism, Models, Biological, Phylogeny, Proteins, Reproducibility of Results, Neural Networks, Computer

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