Visualizing Critical Trails of Scientific Knowledge: Mapping Paradigm Shifts

1. Visualizing Critical Trails of Scientific Knowledge Chaomei Chen, Drexel University Panel on Mapping Science Society for Social Studies of Science Annual Meeting in Pasadena, 20-22 October, 2005

2. Questions • How does scientific knowledge evolve? • If there is a such thing as a paradigm, where can we find its fingerprints, footprints, or both? • Can we X-ray or video type the evolution of scientific knowledge and find the most critical pathways? • Can we make science maps so that one could see where intellectual sharp turns were made, conceptual gulfs were bridged, and lessons learned were diffused?

3. Approach • Social networks • Weak ties, structural holes, knowledge diffusion • Intellectual networks • Research fronts, intellectual bases, conceptual revolutions, paradigm shifts, turning points • CiteSpace – an evolving tool for detecting and visualizing emergent trends and changes in scientific literature • Citation networks, co-citation network, hybrid networks • Examples • Conceptual revolutions: string theory; accelerating universe • Scientific debates: mass extinctions; global warming • Response to external events: terrorist attacks • Scientific evidence: NSAID or Vioxx

4. Social Networks: Weak ties and Structural Holes

5. “Creativity is the friction of the attention space at the moments when the structural blocks are grinding against one another the hardest” • The philosophers of greatest repute tended to be rivals representing conflicting schools of thought for their generation. Collins 1998, p. 76

6. Social Network of Coauthorship

7. Weak Components 3 C 2 1 B A Betweenness Centrality Structural Hole Measures Core/Periphery Class Density matrix 1 2 ----- ----- 1 0.280 0.007 2 0.007 0.002

8. Structural and Temporal Patterns • Are maps valid representations of scientific fields or of science as a whole, and what are the viable approaches to validation? • Terrorism (1990-2004), domain experts at pivotal points • String theory (1990-2004), domain experts at pivotal points • What social and intellectual realities do they capture, or fail to capture? • IST co-authorship (1990-2005) • Can scientific controversies be represented by maps and what do they look like? • Global warming debates • Mass extinctions debates • Vioxx, evidence • Can maps inform us about the history of a field? • Terrorism, Mass extinctions • Do they reflect a “collective mind” of science, or are they merely artifactual aggregates of particularistic behavior? • Finally, what is the audience for such maps: the scientific elite or the masses?

9. An animation of botox researchhttp://www.pages.drexel.edu/~cc345/video/citation_land_local.avi

10. Intellectual Networks

11. The Approch • Structural and Temporal Analysis • Intellectual turning points • Emerging themes before … after!

12. Why Scientists Cite? • Normative View • Citations are made because of the intellectual values of cited works. • They should not be affected by social and cultural characteristics such as race, gender, or academic rank.

13. Why Scientists Cite? • Social Constructivist View • Scientific knowledge is socially constructed and motivated by political and rhetorical reasons. • Scientists use citations primarily as tools of persuasion. • Citations serve as a vehicle to enlist the support of eminent authors and win over readers.

14. Why Scientists Cite? • Which way is it? • Stewart, J. A. Drifting Continents and Colliding Paradigms: Perspectives on the Geoscience Revolution. Indiana University Press, 1990. • Baldi, S. Normative versus social constructivist processes in the allocation of citations: A network-analytic model. American Sociological Review, 63 (6). 829-846. • White, H.D., Wellman, B. and Nazer, N. Does citation reflect social structure? Longitudinal evidence from the 'Gobenet' interdisciplinary research group. Journal of the American Society for Information Science and Technology, 55 (2). 111-126. • Scientists tend to cite papers because of their intellectual values!

15. What Scientists Cite? • Foundational papers • Recent papers foundational recent

16. What Scientists Cite? • Foundational papers • Recent papers Hargens, L.L. Using the Literature: Reference Networks, Reference Contexts, and the Social Structure of Scholarship. American Sociological Review, 65 (6). 846-865. foundational recent sociology, psychology physics, biomedicine

17. Paradigm Shift • Normative • Citations reflect intellectual values. • Recentness • Citations register new concepts and new associations. turning point

18. CiteSpace • Multipartite networks • Author, Article, Keyword • Co-authorship, co-citation, citation • Time Slicing • Filter out the effects of long-range citations • Divide and conquer • Threshold-Based Interpolating • Select the cream of the crop across the board • Burst Detection • Surge of node attributes, surge of link attributes • Pruning • Minimum Spanning Tree • Pathfinder Network Scaling • Graph-Theoretical Analysis and Clustering • Centrality • Citation Half-Life

19. CiteSeer ACM DL Google Scholar Web of Science PubMed Topic search “terrorism”

20. Design citing author citing author co-authorship cited author or paper cited author or paper annual citations cocitation topic-reference topic-reference surge extracted keyword extracted keyword MST centrality Pathfinder

21. Thematic grouping Intellectual turning points Thematic change over time Abrupt changes associated with triggers Expected Patterns

22. Validated by Experts • String Theory • Physicists • Terrorism • Physiatrists • Medicine • Political Science • Mass Extinction • Ocean Paleontologist

24. DCA ACA Co-Term (Burst) Co-Authorship JCA

25. 1994-2004N=469, E=1,798

30. 11 Stress Disorders, Post-Traumatic/*epidemiology 9 Terrorism/*psychology 8 Disasters 27 Biological Warfare 17 Violence 14 Bioterrorism N=45 N=93 N=31 11 Explosions 7 Violence 4 Blast Injuries/*mortality

31. Evolving over time

43. MeSH

44. Summary • Scientific literature reflects the underlying changes in scientific paradigms. • Deeper processing is necessary to sharpen the big picture of intellectual changes. • Given the structural and temporal scale, complexity, and dynamics of a knowledge domain, there is still a long way to go to turn a challenging and fascinating ambition to pragmatic and everyday tools and applications.

45. The CiteSpace Homepagehttp://cluster.cis.drexel.edu/~cchen/citespace