Digital Library (DL)

1. Digital Library (DL) Source: Information Processing & Management, Special Issue, May 1999, by G. Marchionini of UNC at Chapel Hill, and Ed Fox of VT • Recap of “best of” phase I, and glimpses of phase II • Albeit the many aspects of research in DL, focus for this lecture is on Access and Visualization

2. Digital Library (DL) Def: Research/application of digital technology to the information problems addressed by institutions such as libraries, museums, schools, and publishers Common features • Sharable resources • Large/Integrating across DLs, “middleware” • Multiple stakeholders

3. Journal Components Source: Ann Peterson Bishop from University of Illinois at Urbana-Champaign • Typical Components are: Figures, Conclusions, References, Table of Content,. • Research focus on: Identify, retrieve, use, read • Prototype (DeLIver) searches by component • Learned from users: • Components help decide whether read/obtain FT • Components offer a synopsis/hints for content

4. Journal Components (cont.) • Conclusions • Nature of component use complex, and depends on user type • Is used during all stages of search/retrieval • Components act as “metadata” • Disassambly and reassambly is common practice • Extend search capabilities on components desirable

5. Requirements for Remote Access Source: Robert Downs of Montclair State University • Most scholars prefer text, and selective print • Prefer search terms boldfaced in retrieved doc. Like the “Find” feature of browser • Prefer natural language queries over Boolean/SQL • Work with small no. of docs, read and print

6. Meta-Search Engines • In principle, they would diagnose which sear-engine(s) to use based on the query/topic, user profile, search strategy,.. • March Chignell et.al., from The University of Toronto conducted an evaluation of them: • Performance of meta-search engines depends on a basic level of performance of search engines • Visualization of results obtained from meta-search engines needs to be improved

7. Visualization of DL Output • Latent Semantic Indexing • Pathfinder Network Scaling • Spatial maps • Author co-citation maps • More work is needed in evaluating the usability of such visualization paradigms in realistic digital library environments

8. Z39.50 • Def: A standard composed of specifications for computer-to-computer linkage between different information retrieval systems. • Purpose: Encode the messages required to communicate between two computers for information search and retrieval purposes • Beginnings: Exchange bibliographic information regardless of the structure of the underlying data

9. Z39.50 Services • Initialize • Create a Z39.50 association; e.g., defines how the origen must operate • Access control (pasw.) or Resource control (confirm) • Target negotiates these service parameters • Search • Type 0: requires private agreement on query form • Type 1: standard Boolean query • Present, Delete, and Release

10. Applications • Wide Area Information Servers (WAIS) • First full-text information retrieval architecture composed of the client, the server, the database, and the protocol • Added format types, s.a., gif and postscript • Library of Congress, OCLC, UC, Dartmouth • Weakness: Lack of help or instructions for searching the database • Zweb, CNIDR, OCLC, AIDS,..