Chapter One - Center for the Study of Digital Libraries
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Transcript Chapter One - Center for the Study of Digital Libraries
Planning a
digital library
How to Build a Digital Library
Ian H. Witten and David Bainbridge
Planning a Digital Library
Responsibilities
Technology to be used
Metadata standard to be used
Greenstone, DSpace, Fedora, Eprints
Dublin Core, METS, etc.
Types of access
Retrospective or Born Digital?
Responsibilities
Legal Issues
Distributing information carries responsibilities
Copyright
Social Issues
Respect customs of the community
Both source and use communities
Ethical issues
Ideology
Ideology – a clear conception of what you plan
to achieve with the collection of information
Ideology of a Collection:
Purpose
Objectives
Principles
guide what is to be included in the collection
Placed in Introduction to Digital Library
Document versus Work
Work
Document
The disembodied content of a message
Pure information
Traditional library: a physical object that embodies the work
Digital library: a particular electronic encoding of a work
How are distinctions made between different
manifestations of a single work?
Converting an Existing Library
Digitizing an existing paper-based collection is
the most expensive kind of project
Consider whether it is worth the effort and
expense
16th Century Mexican Library
Incunabula
Broadsides
Advantages of Digital Libraries
Easier to access remotely than conventional
libraries
Powerful search and browsing
Easier to add additional services
Easier to organize and reorganize
Easier to maintain?
Easier to preserve?
Does your collection have these advantages?
Questions to Address
Will the digital library coexist with an existing
physical one?
What is the collection’s growth rate?
How dynamic is the collection?
Should you consider outsourcing the whole
digital library operation?
Could user needs be satisfied in alternative ways?
Prioritizing Materials
Special collections and unique materials
High use items
Rare books and manuscripts
Research and teaching materials
Low-use items
Criteria for Digital Conversion
Intellectual content
Educational value
Classroom support
Background reading
Distance education
Institutional
Scholarly value
Desire to enhance access to information
Funding available
Resource sharing
Promote strengths of an institution
Reduce handling of fragile originals
Cost and space savings
Building a New Collection
New material
The copyright holder may be the best one to create a
digital collection
Metadata
Where will it come from?
Bibliographic Entities
Documents
Works
Editions
Electronic documents use terms such as version, release and
revision
Authors
Distinction between document and work
Authority control – standardized names for authors
Titles
Attributes of works
Bibliographic Entities
Subjects
Two approaches to automatically assign subject:
Literary and artistic works
Style, form, content, genre
Library of Congress Subject Headings (LCSH)
Key-phrase extraction
Key-phrase assignment
Controlled vocabularies: 30,000 pages, 2,000,000 entries
Hierarchical relationship of broader and narrower topics
Subject classifications
Traditional libraries have a linear arrangement
Digital collection can be rearranged at the click of a mouse
Digitizing Documents
Digitization
The process of taking traditional library materials
and converting them to electronic form
Allows storage and manipulation by a computer
The process is time-consuming and expensive
Stages of Digitization
Scanning
Creates a digitized image of each page
Usually presented to the user
Optical Character Recognition (OCR)
Creates an encoded representation of the textual
content of the pages
Necessary for full-text indexing
Allows searching
Decisions in Scanning
Black-and-white, grayscale or color
Resolution
number of pixels per linear unit
Bits per pixel
Monochrome display: 16 or 256 levels of gray
Color display: up to 24 or 32 bpp
Quality
Increases storage space and time to access
Optical Character Recognition
Manual cleanup is necessary
Less efficient than manual keying when error
rate drops below 95 percent
Interactive OCR
Optical character recognition should be done as an
interactive process
Acquisition
Cleanup
Examine layout
Recognition
Filtering, deskewing and manual cleanup of unwanted areas
Page analysis
Input from scanner or read a file
The “OCR” part
Checking
Saving
Plain text, HTML, RTF, PDF, MS Word
Page Handling
Unbinding
Microfiche or microfilm
Two most expensive parts
Handling the paper
OCR
Planning a Digitization Project
Outsourcing
Cost
$1 to $2 for scanning and OCR
Quality control
Verification