This document discusses URL identifiers and solutions to problems with URLs not being persistent when resources move. It describes PURL and DOI as persistent identifier systems. PURL uses a resolver address and name component to redirect to current URLs. DOI assigns a persistent identification number to registered intellectual content and uses a DOI prefix and suffix. DOIs ensure persistence by resolving to current URLs through simple or multiple resolution methods.
2. Background
Resource Identification- A first step to gain access.
-Book: ISBN, UPC
-Periodicals/Journals-ISSN
Similar Identification system also require for the
digital environment.
3. URL(Uniform Resource Locator)
It is an address of the resource located anywhere over
the Internet.
Uniform: Unique
Resource: Anything that has entity
Identifier: An object that can act as a reference to
something that has an identity
4. Component of URl
Syntax: <scheme>:<scheme-specific-part>
The scheme may be :
ftp :File Transfer protocol
http: Hypertext Transfer Protocol
https: Hypertext Transfer Protocol Secured
mailto: Electronic mail address
telnet :Reference to interactive sessions
File: Host-specific file names
Example: http://www.suniv.ac.in
5. Problem Associated with URL
URL are not persistence and resource can lost, if
the server moves to a new computer
the server moves to a new port on the same computer
the name of the computer the server runs on changes
the resource's name changes
the resource moves to a new server
6. The Solutions
A permanent URL which persistence.
There are many solutions : PURL, Handle System, DOI
etc.
We shall cover the PURL and DOI in detail.
7. PURL
PURL(Persistent Uniform Resource Locator)
A project by OCLC
Three Component :
Protocol
Resolver address
Name
Example: http://purl.oclc.org/SU/PG_DLIS
9. Digital Object Identifier
An identification system for intellectual property in
the digital environment.
Developed by the DOI foundation to provide a
framework for managing intellectual content, link
customers with publisher.
Provides a persistent identification number to each
resource registered with DOI registration agencies.
10. Component of DOI DOI Prefix:
Two component: 10.<organization assigned number>
DOI Suffix
Identification for the entity, it may be a number, ISBN etc.
11. DOI Resolution
Ensures persistence by resolving the DOI to a current
associated value such as a URL;
Resolution may be :
Simple Resolution
Multiple Resolution
14. Benefits of DOI Systems
Persistence, persistence, persistence!!!
DOIs are easy to use. Simply click one or cut and paste
it like you would a URL
Called the “barcode for intellectual property”
Multiple resolution capability leads to more options
for researchers.