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,..