Lennart Björneborn

Department of Information Studies
Royal School of Library and Information Science 

PhD Dissertation

Small-World Link Structures across an Academic Web Space
- a Library and Information Science Approach

The dissertation received the 2004 ASIST/ProQuest Doctoral Dissertation Award from the American Society for Information Science and Technology.

Complete thesis available as PDF file [6.0 MB]:
- http://vip.db.dk/lb/phd/phd-thesis.pdf

Also available chapter-wise as separate PDF files:
- Abstract, prelude, ToC [0.4 MB]
- Chapter 1: Introduction [0.2 MB]
- Chapter 2: Webometrics [0.4 MB]
- Chapter 3: Small-world networks [0.7 MB]
- Chapter 4: UK link data [0.7 MB]
- Chapter 5: Basic graph measures [1.2 MB]
- Chapter 6: Five-step methodology [1.9 MB]
- Chapter 7: Discussion and perspectivation [0.9 MB]
-  -  Section 7.5: Implications for LIS [0.2 MB]
- Chapter 8: Conclusion [0.3 MB]
- References [0.2 MB]
- Appendices [0.9 MB]

Detailed table of contents:
- http://vip.db.dk/lb/phd/toc.htm 

Some pictures from the PhD defence, 5 March 2004:
- http://itlab.dbit.dk/db/billeder/2004.03.05-lennart/ 
- http://itlab.dbit.dk/db/billeder/2004.03.05-lennart/billed-2.html 
- http://itlab.dbit.dk/db/billeder/2004.03.05-lennart/billed-3.html 
- http://itlab.dbit.dk/db/billeder/2004.03.05-lennart/billed-4.html 

PowerPoint presentation at the PhD defence:
- http://vip.db.dk/lb/phd/phd-presentation.ppt [2.4 Mb]

Assessment committee

• Professor Ronald Rousseau, Dept. of Industrial Sciences and Technology, Catholic School for Higher Education Bruges-Ostend, Belgium
• Professor Olle Persson, Dept. of Sociology, Umeå University, Sweden
• Associate Professor Niels Ole Pors, Royal School of Library and Information Science

• Professor Peter Ingwersen, Royal School of Library and Information Science

• Reader Mike Thelwall, University of Wolverhampton, UK

Summary

The dissertation is concerned with small-world link structures in the shape of short link distances across an academic web space through paths of links from web site to web site. Small-world web spaces are concerned with core library and information science (LIS) issues as navigability and accessibility of information across vast document networks containing self-organizing macro-structures constructed through distributed knowledge organization by millions of local web actors. For instance, short link distances affect the speed and exhaustivity with which web crawlers can reach and retrieve web pages when following links from web page to web page.

The main research question is concerned with what types of web links, web pages and web sites function as connectors across dissimilar topical domains in an academic web space. The dissertation is situated within the new research field of webometrics concerned with the study of quantitative aspects of the construction and use of information resources, structures and technologies on the Web, drawing on bibliometric and informetric approaches. The dissertation incorporates approaches from graph theory and social network analysis into this framework.

The dissertation introduces a 'corona' web graph model and a five-step methodology in order to sample, identify and characterize small-world properties by ‘zooming’ stepwise into more and more fine-grained web node levels among 7669 subsites harvested at 109 UK universities. Detailed case studies comprise 10 shortest path nets containing all shortest link paths in both directions between five pairs of topically dissimilar subsites. Indicative findings suggest that personal link creators, such as researchers and students, as well as computer science-related subsites may be important connectors across sites and topics in the investigated academic web space.

A metaphor of crumpled-up paper is used to conceptualize small-world network structures. Further, the dissertation gives an intuitive support to how the Web may be conceived as a web of genres with a rich diversity of interlinked page genres and with genre drift, that is, changes in genres of pages along link paths. The dissertation discusses hypothesized complementarities of topical uniformity and diversity  (including topic drift and genre drift) in the formation of small-world link structures. It is argued there is a need for extending the traditional overall aim and explanatory framework of LIS research, so it encompasses both convergent (goal-directed) and divergent (serendipitous) information behavior conducted by users in both ‘top-down’- and ‘bottom-up’-constructed information systems.

© Björneborn 2004. The Corona model with examples of link paths between different graph components in a web space (modified after the Bow-Tie model by Broder et al. 2000).

• Links are for use – the very essence of hypertext;
• Every surfer his or her link
  – the rich diversity of links across topics and genres;
• Every link its surfer – ditto;
• Save the time of the surfer
  – visualizing web clusters and small-world shortcuts;
• The Web is a growing organism
  
  © Björneborn 2004
  
  cf. Ranganathan (1931). The five laws of library science:
  “Books are for use. Every reader his or her book. Every book its reader. Save the time of the reader. The Library is a growing organism.”