Transcript Digital Library (DL)

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
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
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
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
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
Meta-Search Engines
• In principle, they would diagnose which searengine(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 metasearch engines needs to be improved
Visualization of DL Output
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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
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
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
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,..