1. AuthorLink: Instant Author Co-Citation Mapping for Online Searching Xia Lin Howard D. White Jan Buzydlowski Xlin@drexel.edu Drexel University Philadelphia, PA, USA

2. Presented at the National Online Meeting Online 2001 At New York, May 15-17, 2001.

3. Author Search A tradition from library catalogs –Card Catalog –Online Catalog –Bibliographical Databases –Full text Databases Two basic approaches for author searching –String matching in the author field –Alphabetical indexing/browsing

4. Problems of Author Searching How to search for related authors? –There are no easy solutions in most current systems. The searcher usually needs to do a lot of intellectual work to get to other related authors’ works Follow the citations Follow the subjects

5. Our Approach Always show related authors during the author search –Put the targeted author among relevant related authors –Visualize how these authors are related to each other –Use the author groupings to reveal subject areas

6. A Map of Information Scientists

7. Plato

8. The AuthorLink System Built on a significantly large database –ISI Arts and Humanities Database (AHCI) 1988 - 1997 1.26 million records –Real time mapping and visualizing Based on two key methodologies –Author Co-Citation Analysis –Information Visualization

9. Co-Citation Co-citation is the mentioning of any two earlier documents in the bibliographic references of a later third document. Later Document 3 Document 1 cites Document 2 cites

10. Co-Citation Analysis The count of mentions may grow over time as new writings appear. Thus, co-citation counts can reflect citers’ changing perceptions of documents as more or less strongly related. Documents shown to be related by their co-citation counts can be mapped as proximate in intellectual space.

11. Co-Citation Mapping Detects patterns in the frequency with which any works by any two authors are jointly cited in later works. Only recurrent co-citation is significant: The more times authors are cited together, the more strongly related they are in the eyes of citers.

12. Example If Ben Shneiderman and Shakespeare are cited together in one article, it probably means little. If Ben Shneiderman and Stuart Card are cited together in 205 articles,* it means a lot: their conjoined names have come to symbolize something like “interactive interfaces for digital libraries.” Possibly no subject heading captures this concept. * Actual count, 7/10/00 In a cited-author (CA) search on Dialog, SELECT CA=SHNEIDERMAN B AND CA=CARD SK would retrieve the 205 citing articles.

13. Use DIALOG for ACA Selection of authors Retrieval of co-citation frequencies Compilation of raw co-citation matrix Conversion to a correlation matrix Multivariate analysis of correlation matrix (using principle components analysis, cluster analysis, and multidimensional scaling).

14. The Old Interface

15. The AuthorLink System An integrated system that, in seconds, –Finds and ranks 24 authors most often cited with seed author –Pairs all ranked authors systematically, performs co-citation searches for all pairs, and generates a data matrix containing the results. –Maps the co-citation counts in the matrix and generates interface maps for the user. Kohonen self-organizing maps (SOMs) Pathfinder Networks (PFNETs) Live interface can be used to retrieve documents from AHCI that cite paired authors

16. Architecture of AuthorLink Front tier.. Middle tier.. Back tier BRS Search Engine Web Server JavaServlets Web-based Map Interface Java Applet Mapping Procedures Application Server Oracle Database MYSQL Database

17. Live System Demo AuthorLink

18. More Features of AuthorLink AuthorLink presents an overview of a field or a subject area. AuthorLink can distinguish similar author names that are otherwise conflated in ISI data. AuthorLink makes it easy for the user to explore intellectual territories from a single seed name, which minimizes cognitive load.

19. Overview Features of AuthorLink

20. Einstein-A and Mozart (Music)

21. Einstein-A and Niels Bohr (Physics)

22. AuthorLink helps to explore new territories

23. Beyond AuthorLink ConceptLink –Maps medical subject headings (MeSH) –Uses PUBMED as the backend search engine –Uses UMLS co-occurrence counts JournalLink –Developed in the same database as AuthorLink to visualize journal relationships

24. ConceptLink

26. Query: “back pain”

27. Live System Demo ConceptLink

28. Future Development Stress browsability –AuthorLink and ConceptLink are not only search tools but also exploration and discovery tools Develop middleware and interfaces that can be linked to any search engine –All ISI databases –DIALOG databases –Web search engines