Difference between revisions of "Digital library" - New World Encyclopedia

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A '''digital library''' is a [[library]] in which collections are stored in digital formats (as opposed to print, [[microform]], or other media) and accessible by computers.<ref>Greenstein, Daniel I., Thorin, Suzanne Elizabeth. [http://www.clir.org/PUBS/reports/pub109/pub109.pdf The Digital Library: A Biography]. Digital Library Federation (2002) ISBN 1933645180. Accessed June 25, 2007.</ref> The digital content may be stored locally, or accessed remotely via computer networks. A digital library is a type of [[information retrieval]] system.
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A '''digital library''' is a [[library]] in which collections are stored in digital formats (as opposed to print, [[microform]], or other media) and accessible by computers.<ref>Daniel I. Greenstein and Suzanne Elizabeth Thorin, [http://www.clir.org/PUBS/reports/pub109/pub109.pdf The Digital Library: A Biography,] Digital Library Federation (2002). ISBN 1933645180. Retrieved June 25, 2007.</ref> The digital content may be stored locally, or accessed remotely via computer networks. A digital library is a type of [[information retrieval]] system.
A digital library has a number of advantages and problems not found in a traditional library. Some of the advantages are that there are no physical limits to information storage, materials can be accessed round the clock by multiple users, and they feature efficient information retrieval mechanisms. Some of the problems unique to a digital library include the need for periodical [[data migration]] due to constant and rapid technological advancement of information technology, as well as issues concerning copyright infringement. Nevertheless, library and information professional communities are pursuing a workable model of a digital library and a number of initiatives have been made both in the public and private sectors. For example, [[Google]] collaborated with a number of major [[academic library|academic libraries]] and made a large number of library holdings available to internet users under the [[Google Books Library Project]].  
 
  
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A digital library has a number of advantages and problems not found in a traditional library. Some of the advantages are that there are no physical limits to information storage, materials can be accessed around the clock by multiple users, and they feature efficient [[information retrieval]] mechanisms. Some of the problems unique to a digital library include the need for periodical [[data migration]] due to constant and rapid technological advancement of information technology, as well as issues concerning copyright infringement. Nevertheless, library and information professional communities are pursuing a workable model of a digital library and a number of initiatives have been made both in the public and private sectors. For example, [[Google]] collaborated with a number of major [[academic library|academic libraries]] and made a large number of library holdings available to internet users under the [[Google Books Library Project]].
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{{toc}}
 
==Terminology==
 
==Terminology==
The first use of the term ''digital library'' in print may have been in a 1988 report to the [[Corporation for National Research Initiatives]]<ref>Kahn, R. E., & Cerf, V. G. (1988). [http://hdl.handle.net/4263537/2091 The Digital Library Project Volume I: The World of Knowbots, (DRAFT): An Open Architecture For a Digital Library System and a Plan For Its Development]. Reston, VA: Corporation for National Research Initiatives. Retrieved June 6, 2008.</ref> The term ''digital libraries'' was first popularized by the [[National Science Foundation|NSF]]/[[DARPA]]/[[NASA]] Digital Libraries Initiative in 1994.<ref>Edward A. Fox. [http://www.asis.org/Bulletin/Oct-99/fox.html The Digital Libraries Initiative - Update and Discussion], Bulletin of the America Society of Information Science, Vol. 26, No 1, October/November 1999. Retrieved June 6, 2008.</ref> The older names '''electronic library''' or '''virtual library''' are also occasionally used, though ''electronic library'' nowadays more often refers to portals, often provided by government agencies, as in the case of the [http://www.flelibrary.org Florida Electronic Library].
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The first use of the term "digital library" in print may have been in a 1988 report to the [[Corporation for National Research Initiatives]]<ref>R.E. Kahn and V.G. Cerf [http://hdl.handle.net/4263537/2091 The Digital Library Project Volume I: The World of Knowbots, (DRAFT): An Open Architecture For a Digital Library System and a Plan For Its Development.] Retrieved June 6, 2008.</ref> The term "digital libraries" was first popularized by the [[National Science Foundation|NSF]]/[[DARPA]]/[[NASA]] Digital Libraries Initiative in 1994.<ref>Edward A. Fox. [http://www.asis.org/Bulletin/Oct-99/fox.html The Digital Libraries Initiative—Update and Discussion,] ''Bulletin of the America Society of Information Science,'' Vol. 26, No 1, October/November 1999. Retrieved June 6, 2008.</ref> The older names '''electronic library''' or '''virtual library''' are also occasionally used, though "electronic library" nowadays more often refers to portals, often provided by government agencies, as in the case of the Florida Electronic Library.<ref>Florida Electronic Library, [http://www.flelibrary.org/about.php About Us]. Retrieved January 29, 2014.</ref>
  
 
==Types of digital libraries==
 
==Types of digital libraries==
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The term "digital library" is diffuse enough to be applied to a wide range of collections and organizations, but to be considered a digital library an online collection of information must be managed by and made accessible to a community of users. Thus, only some web sites can be considered true digital libraries. Many of the best known digital libraries are older than the Web including [[Perseus Project|Project Perseus]], [[Project Gutenberg]], and [[ibiblio]]. Nevertheless, as a result of the development of the internet and its search potential, digital libraries such as [[the European Library]] and the [[Library of Congress]] are now developing in a Web-based environment. Public, school and college libraries are also able to develop digital download websites, featuring [[eBook]]s, [[audiobook]]s, music and video, through companies like [[OverDrive, Inc.]]
  
The term ''digital library'' is diffuse enough to be applied to a wide range of collections and organizations, but to be considered a digital library an online collection of information must be managed by and made accessible to a community of users. Thus, only some web sites can be considered true digital libraries. Many of the best known digital libraries are older than the web including [[Perseus Project|Project Perseus]], [[Project Gutenberg]], and [[ibiblio]]. Nevertheless, as a result of the development of the internet and its search potential, digital libraries such as [[the European Library]] and the [[Library of Congress]] are now developing in a web-based environment. Public, school and college libraries are also able to develop digital download websites, featuring [[eBooks]], [[audiobooks]], music and video, through companies like [[OverDrive, Inc.]]
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A distinction is often made between content that was created in a digital format, known as [[born-digital]], and information that has been converted from a physical medium, for example, paper, by [[digitization|digitizing]]. The term "hybrid library" is sometimes used for libraries that have both physical collections and digital collections. They consist of a combination of traditional preservation efforts such as microfilming and new technologies involving digital projects. For example, [[American Memory]] is a digital library within the [[Library of Congress]]. Some important digital libraries also serve as long term archives, for example, the [[ePrint]], [[arXiv]], and the [[Internet Archive]].
 
 
A distinction is often made between content that was created in a digital format, known as [[born-digital]], and information that has been converted from a physical medium, e.g., paper, by [[digitization|digitizing]]. The term ''hybrid library'' is sometimes used for libraries that have both physical collections and digital collections. They consist of a combination of traditional preservation efforts such as microfilming and new technologies involving digital projects. For example, [[American Memory]] is a digital library within the [[Library of Congress]]. Some important digital libraries also serve as long term archives, for example, the [[ePrint]] [[arXiv]], and the [[Internet Archive]].
 
  
 
===Academic repositories===
 
===Academic repositories===
Many academic libraries are actively involved in building [[Institutional repository|institutional repositories]] of the institution's books, papers, theses, and other works which can be digitized or were 'born digital'. Many of these repositories are made available to the general public with few restrictions, in accordance with the goals of [[open access]]. Institutional, truly free, and corporate repositories are often referred to as digital libraries.
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Many academic libraries are actively involved in building [[Institutional repository|institutional repositories]] of the institution's books, papers, theses, and other works which can be digitized or were "born digital." Many of these repositories are made available to the general public with few restrictions, in accordance with the goals of [[open access]]. Institutional, truly free, and corporate repositories are often referred to as digital libraries.
  
 
===Digital archives===
 
===Digital archives===
 
[[Archives]] differ from libraries in several ways. Traditionally, archives were defined as:
 
[[Archives]] differ from libraries in several ways. Traditionally, archives were defined as:
  
# Containing primary sources of information (typically letters and papers directly produced by an individual or organization) rather than the secondary sources found in a library (books, etc);
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# Containing primary sources of information (typically letters and papers directly produced by an individual or organization) rather than the secondary sources found in a library (books, papers, journals, and so on)
# Having their contents organized in groups rather than individual items. Whereas books in a library are cataloged individually, items in an archive are typically grouped by provenance (the individual or organization who created them) and original order (the order in which the materials were kept by the creator);
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# Having their contents organized in groups rather than individual items. Whereas books in a library are cataloged individually, items in an archive are typically grouped by provenance (the individual or organization who created them) and original order (the order in which the materials were kept by the creator)
# Having unique contents. Whereas a book may be found at many different libraries, depending on its rarity, the records in an archive are usually one-of-a-kind, and cannot be found or consulted at any other location except at the archive that holds them.
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# Having unique contents. Whereas a book may be found at many different libraries, depending on its rarity, the records in an archive are usually one-of-a-kind, and cannot be found or consulted at any other location except at the archive that holds them
  
The technology used to create digital libraries has been even more revolutionary for archives since it breaks down the second and third of these general rules. The use of [[search engines]], [[Optical Character Recognition]] and [[metadata]] allow digital copies of individual items (i.e. letters) to be cataloged, and the ability to remotely access digital copies has removed the necessity of physically going to a particular archive to find a particular set of records. The [[Oxford Text Archive]] is generally considered to be the oldest digital archive of academic primary source materials.
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The technology used to create digital libraries has been even more revolutionary for archives. since it breaks down the second and third of these general rules. The use of [[search engines]], [[Optical Character Recognition]], and [[metadata]] allow digital copies of individual items (such as letters) to be cataloged, and the ability to remotely access digital copies has removed the necessity of physically going to a particular archive to find a particular set of records. The [[Oxford Text Archive]] is generally considered to be the oldest digital archive of academic primary source materials.
  
[[Project Gutenberg]], [[Google Book Search]], [[Windows Live Search Books]], [[Internet Archive]], [[Cornell University]], the Library of Congress [[World Digital Library]], the Digital Library at the [[University of Michigan]], and CMU's [[Universal library]] are considered leaders in the field of digital archive creation and management. There are hundreds of regionals such as the [[Wisconsin Historical Society]]. The [[Holy See|Vatican]] maintains an extensive digital library inventory and associated technology. The entire works of [[Martin Luther]] are held at [[Emory University]] and are being digitized under an $8M Grant from Coca-Cola heirs, and the [[Packard Foundation]] maintains digitization facilities near the Acropolis in [[Athens, Greece]].
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[[Project Gutenberg]], [[Google Book Search]], [[Windows Live Search Books]], [[Internet Archive]], [[Cornell University]], the Library of Congress [[World Digital Library]], the Digital Library at the [[University of Michigan]], and CMU's [[Universal library]] are considered leaders in the field of digital archive creation and management. There are hundreds of regional digital archives, such as the [[Wisconsin Historical Society]]. The [[Holy See|Vatican]] maintains an extensive digital library inventory and associated technology. The entire works of [[Martin Luther]] are held at [[Emory University]] and are being digitized under an $8M Grant from Coca-Cola heirs, and the [[Packard Foundation]] maintains digitization facilities near the Acropolis in [[Athens, Greece]].
  
 
===The future===
 
===The future===
Large scale digitization projects are underway at [[Google]], the [[Million Book Project]], [[MSN]], and [[Yahoo!]]. With continued improvements in book handling and presentation technologies such as  [[optical character recognition]] and [[ebook]]s, and development of alternative depositories and business models, digital libraries are rapidly growing in popularity as demonstrated by Google, Yahoo!, and MSN's efforts. Just as libraries have ventured into audio and video collections, so have digital libraries such as the [[Internet Archive]].
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Large scale digitization projects are underway at [[Google]], the [[Million Book Project]], [[MSN]], and [[Yahoo!]] With continued improvements in book handling and presentation technologies, such as  [[optical character recognition]] and [[ebook]]s, and development of alternative depositories and business models, digital libraries are rapidly growing in popularity as demonstrated by Google, Yahoo!, and MSN's efforts. Just as libraries have ventured into audio and video collections, so too have digital libraries, such as the [[Internet Archive]].
  
 
==Search mechanism==
 
==Search mechanism==
Most digital libraries provide a search interface which allows resources to be found. These resources are typically [[deep web]] (or invisible web) resources since they frequently cannot be located by [[search engine]] [[web crawler|crawlers]]. Some digital libraries create special pages or [[sitemap]]s to allow search engines to find all their resources. Digital libraries frequently use the [[Open Archives Initiative Protocol for Metadata Harvesting]] (OAI-PMH) to expose their metadata to other digital libraries, and search engines like [[Google Scholar]], [[Google]], [[Yahoo!]] and [[Scirus]] can also use OAI-PMH to find these deep web resources<ref>Koehler, AEC. ''Some Thoughts on the Meaning of Open Access for University Library Technical Services'' Serials Review Vol. 32, 1, 2006, p. 17</ref>.
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Most digital libraries provide a search interface which allows resources to be found. These resources are typically [[deep Web]] (or invisible Web) resources since they frequently cannot be located by [[search engine]] [[web crawler|crawlers]]. Some digital libraries create special pages or [[sitemap]]s to allow search engines to find all their resources. Digital libraries frequently use the [[Open Archives Initiative Protocol for Metadata Harvesting]] (OAI-PMH) to expose their metadata to other digital libraries, and search engines like [[Google Scholar]], [[Google]], [[Yahoo!]] and [[Scirus]] can also use OAI-PMH to find these deep web resources.<ref>AEC Koehler, ''Some Thoughts on the Meaning of Open Access for University Library Technical Services'' Serials Review Vol. 32, 1, 2006, p. 17.</ref>
  
 
There are two general strategies for searching a '''federation''' of digital libraries:
 
There are two general strategies for searching a '''federation''' of digital libraries:
#distributed searching, and
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#Distributed searching
#searching previously harvested [[metadata]].
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#Searching previously harvested [[metadata]].
  
 
Distributed searching typically involves a client sending multiple search requests in parallel to a number of servers in the federation. The results are gathered, duplicates are eliminated or clustered, and the remaining items are sorted and presented back to the client. Protocols like [[Z39.50]] are frequently used in distributed searching. A benefit to this approach is that the resource-intensive tasks of indexing and storage are left to the respective servers in the federation. A drawback to this approach is that the search mechanism is limited by the different indexing and ranking capabilities of each database, making it difficult to assemble a combined result consisting of the most relevant found items.
 
Distributed searching typically involves a client sending multiple search requests in parallel to a number of servers in the federation. The results are gathered, duplicates are eliminated or clustered, and the remaining items are sorted and presented back to the client. Protocols like [[Z39.50]] are frequently used in distributed searching. A benefit to this approach is that the resource-intensive tasks of indexing and storage are left to the respective servers in the federation. A drawback to this approach is that the search mechanism is limited by the different indexing and ranking capabilities of each database, making it difficult to assemble a combined result consisting of the most relevant found items.
  
Searching over previously harvested metadata involves searching a locally stored [[search engine indexing|index]] of information that has previously been collected from the libraries in the federation. When a search is performed, the search mechanism does not need to make connections with the digital libraries it is searching - it already has a local representation of the information. This approach requires the creation of an indexing and harvesting mechanism which operates regularly, connecting to all the digital libraries and querying the whole collection in order to discover new and updated resources. [[OAI-PMH]] is frequently used by digital libraries for allowing metadata to be harvested. A benefit to this approach is that the search mechanism has full control over indexing and ranking algorithms, possibly allowing more consistent results. A drawback is that harvesting and indexing systems are more resource-intensive and therefore expensive.
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Searching over previously harvested metadata involves searching a locally stored [[search engine indexing|index]] of information that has previously been collected from the libraries in the federation. When a search is performed, the search mechanism does not need to make connections with the digital libraries it is searching—it already has a local representation of the information. This approach requires the creation of an indexing and harvesting mechanism which operates regularly, connecting to all the digital libraries and querying the whole collection in order to discover new and updated resources. [[OAI-PMH]] is frequently used by digital libraries for allowing metadata to be harvested. A benefit to this approach is that the search mechanism has full control over indexing and ranking algorithms, possibly allowing more consistent results. A drawback is that harvesting and indexing systems are more resource-intensive and therefore expensive.
 
 
== Construction and organisation ==
 
  
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== Construction and organization ==
 
===Frameworks===
 
===Frameworks===
 
A digital library can be built around specific repository software. The best known examples of this are  
 
A digital library can be built around specific repository software. The best known examples of this are  
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===Selection Criteria===
 
===Selection Criteria===
A strategy with defined selection priorities for digitization is critical and should be informed by a convergence in the consideration for both preservation and access. The focus should be based on traditional preservation decisions such as the value of materials; the condition of materials; use of materials; and material characteristics ensuring a high level of success. For the Library of Congress, for example, items of national interest are prime candidates and digitizing these objects improves access while reducing the wear and tear on the originals.<ref>Marcum, Deanna B. [http://www.firstmonday.org/issues/issue12_7/marcum/index.html Digitizing for Access and Preservation: Strategies of the Library of Congress], ''First Monday'', volume 12, number 7 (July 2007). Retrieved June 6, 2008.</ref>
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A strategy with defined selection priorities for digitization is critical and should be informed by a convergence in the consideration for both preservation and access. The focus should be based on traditional preservation decisions such as the value of materials; the condition of materials; use of materials; and material characteristics ensuring a high level of success. For the Library of Congress, for example, items of national interest are prime candidates and digitizing these objects improves access while reducing the wear and tear on the originals.<ref>Deanna B. Marcum, [http://www.firstmonday.org/issues/issue12_7/marcum/index.html Digitizing for Access and Preservation: Strategies of the Library of Congress,] ''First Monday,'' volume 12, number 7 (July 2007). Retrieved June 6, 2008.</ref>
  
In the early discussions about digitization of library materials the selection decisions were proposed based on a desire for better access to that item's content and not on the condition or value of the original item.<ref>Gertz, J. (2000 April). Selection for preservation in the digital age: An overview. Library Resources & Technical Services , 44(2), 97-104.</ref> In 2001, Paula De Stefano <ref>De Stefano, Paula. (2001, January). Selection for digital conversion in academic libraries. College & Research Libraries 62(1), 58-69.</ref>wrote that a use-based criteria was promising, as it is “fundamental to collection development and is the common thread in all selection decisions” however her own study showed that use was not the most popular approach – in fact, most digital projects at the time focused on special collections, which are generally not the most popular items in the overall collection.  
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In the early discussions about digitization of library materials, the selection decisions were proposed based on a desire for better access to that item's content and not on the condition or value of the original item.<ref>J. Gertz, Selection for preservation in the digital age: An overview, ''Library Resources & Technical Services'' 44(2): 97-104.</ref> In 2001, Paula De Stefano<ref>Paula De Stefano, Selection for digital conversion in academic libraries, ''College & Research Libraries'' 62(1): 58-69.</ref>wrote that a use-based criteria was promising, as it is “fundamental to collection development and is the common thread in all selection decisions” however her own study showed that use was not the most popular approach—in fact, most digital projects at the time focused on special collections, which are generally not the most popular items in the overall collection.  
  
The persistent risk of disappearing "last copies"<ref>Silipigni Connaway, L, et. als. (2006, July). Last copies: What's at risk?. College & Research Libraries , 67(4), 370-9.</ref> and the declines seen in the condition of national treasures, as exemplified by the 2005 Heritage Health Index Report on the State of America's Collections<ref>Heritage Preservation, 2005. A Public Trust at Risk: The Heritage Health Index Report on the State of America’s Collections. Washington, D.C.: Heritage Preservation</ref> provide the rationale for establishing priorities and balancing access with preservation needs. The transient nature of electronic information can contribute to a phenomenon called "memory loss." This is a result of data extinctions as technologies become obsolete. There is also a drift away from original bibliographic contexts as time passes.<ref>Teper, Thomas H. "Where Next? Long-Term Considerations for Digital Initiatives." ''Kentucky Libraries.'' 65(2) (2001):12-18.</ref> A 1998 Council on Library and Information Sources white paper<ref>Hazen, Dan C., Jeffrey L. Horrell, and Jan Merrill-Oldham. [http://www.clir.org/pubs/reports/hazen/pub74.html] Selecting Research Collections for Digitization]. Economics of information. Washington, D.C.: Council on Library and Information Resources, 1998ISBN 1887334602 ISBN 9781887334600. Retrieved June 6, 2008.</ref> identified the following comprehensive considerations for selection: assessment of the intellectual and physical nature of the source materials; the number and location of current and potential users; the current and potential nature of use; the format and nature of the proposed digital product and how it will be described, delivered, and archived; how the proposed product relates to other digitization efforts; and projections of costs in relation to benefits.
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The persistent risk of disappearing "last copies"<ref>L. Silipigni Connaway, et al., Last copies: What's at risk? ''College & Research Libraries,'' 67(4): 370-9.</ref> and the declines seen in the condition of national treasures, as exemplified by the 2005 Heritage Health Index Report on the State of America's Collections<ref>Heritage Preservation, ''A Public Trust at Risk: The Heritage Health Index Report on the State of America’s Collections'' (Washington, D.C.: Heritage Preservation).</ref> provide the rationale for establishing priorities and balancing access with preservation needs. The transient nature of electronic information can contribute to a phenomenon called "memory loss." This is a result of data extinctions as technologies become obsolete. There is also a drift away from original bibliographic contexts as time passes.<ref>Thomas H. Teper, "Where Next? Long-Term Considerations for Digital Initiatives," ''Kentucky Libraries'' 65(2) (2001): 12-18.</ref> A 1998 Council on Library and Information Sources white paper<ref>Dan C. Hazen, Jeffrey L. Horrell, and Jan Merrill-Oldham, [http://www.clir.org/pubs/reports/hazen/pub74.html Selecting Research Collections for Digitization,] ''Economics of information'' (Washington, D.C.: Council on Library and Information Resources, 1998, ISBN 1887334602). Retrieved June 6, 2008.</ref> identified the following comprehensive considerations for selection: Assessment of the intellectual and physical nature of the source materials; the number and location of current and potential users; the current and potential nature of use; the format and nature of the proposed digital product and how it will be described, delivered, and archived; how the proposed product relates to other digitization efforts; and projections of costs in relation to benefits.
  
 
===Digitization===
 
===Digitization===
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Analog signals are continuously variable, both in the number of possible values of the signal at a given time, as well as in the number of points in the signal in a given period of time. However, digital signals are discrete in both of those respects, and so a digitization can only ever be an approximation of the signal it represents. The digital representation does not necessarily lose information in this transformation since the analog signal usually contains both information and noise.
 
Analog signals are continuously variable, both in the number of possible values of the signal at a given time, as well as in the number of points in the signal in a given period of time. However, digital signals are discrete in both of those respects, and so a digitization can only ever be an approximation of the signal it represents. The digital representation does not necessarily lose information in this transformation since the analog signal usually contains both information and noise.
  
A digital signal may be represented by a sequence of integers. Digitization is performed by reading an analog signal A, and, at regular time intervals (sampling frequency), representing the value of A at that point by an integer. Each such reading is called a sample.
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A digital signal may be represented by a sequence of integers. Digitization is performed by reading an analog signal, A, and, at regular time intervals (sampling frequency), representing the value of A at that point by an integer. Each such reading is called a sample.
  
 
A series of integers can be transformed back into an analog signal that approximates the original analog signal. Such a transformation is called DA conversion. There are two factors determining how close such an approximation to an analog signal A a digitization D can be, namely the sampling rate and the number of bits used to represent the integers.
 
A series of integers can be transformed back into an analog signal that approximates the original analog signal. Such a transformation is called DA conversion. There are two factors determining how close such an approximation to an analog signal A a digitization D can be, namely the sampling rate and the number of bits used to represent the integers.
  
In the past few years, procedures for digitizing books at high speed and comparatively low cost have improved considerably with the result that it is now possible to plan the digitization of millions of books per year for creating digital libraries.<ref> Committee on Institutional Cooperation: [http://www.cic.uiuc.edu/programs/CenterForLibraryInitiatives/Archive/PressRelease/LibraryDigitization/index.shtml Partnership announced between CIC and Google], 6 June 2007, Retrieved 7 July 2007.</ref>
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In the past few years, procedures for digitizing books at high speed and comparatively low cost have improved considerably with the result that it is now possible to plan the digitization of millions of books per year for creating digital libraries.<ref>Committee on Institutional Cooperation, Partnership announced between CIC and Google.</ref>
  
 
===Collaborative digitization projects===
 
===Collaborative digitization projects===
There are many collaborative digitization projects throughout the United States and in Europe, Australia and Asia (see below). Two of the earliest projects were the [http://www.cdpheritage.org/ Collaborative Digitization Project] in Colorado and [http://www.ncecho.org/ NC ECHO - North Carolina Exploring Cultural Heritage Online], based at the State Library of North Carolina. These projects helped to establish and publish best practices for digitization and work with regional partners to digitize cultural heritage materials. Additional criteria for best practice have more recently been established in the UK, Australia and the European Union<ref>[http://www.ariadne.ac.uk/issue43/awre-rvw/ Digital Libraries: Principles and Practice in a Global] Environment, Ariadne April 2005. Retrieved June 6, 2008.</ref>. [http://wisconsinheritage.org/ Wisconsin Heritage Online] is a collaborative digitization project modeled after the Colorado Collaborative Digitization Project. Wisconsin uses a [http://wiheritage.pbwiki.com/ wiki] to build and distribute collaborative documentation. Georgia's collaborative digitization program, the [http://dlg.galileo.usg.edu/ Digital Library of Georgia], presents a seamless virtual library on the state's history and life, including more than a hundred digital collections from 60 institutions and 100 agencies of government. The [[Digital Library of Georgia]] is a [http://www.galileo.usg.edu GALILEO] initiative based at the University of Georgia Libraries.
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There are many collaborative digitization projects throughout the United States and in Europe, Australia, and Asia. Two of the earliest projects were the Collaborative Digitization Project, in Colorado, and NC ECHO, North Carolina Exploring Cultural Heritage Online, based at the State Library of North Carolina. These projects helped to establish and publish best practices for digitization and work with regional partners to digitize cultural heritage materials. Additional criteria for best practice have more recently been established in the UK, Australia, and the European Union.<ref>Ariadne, [http://www.ariadne.ac.uk/issue43/awre-rvw/ Digital Libraries: Principles and Practice in a Global Environment.] Retrieved June 6, 2008.</ref> Recollection Wisconsin, formerly Wisconsin Heritage Online, is a collaborative digitization project modeled after the Colorado Collaborative Digitization Project. They collaborate with libraries, archives, historical societies, and museums across Wisconsin to facilitate digitization efforts.<ref>Recollection Wisconsin, [http://recollectionwisconsin.org/organizations/guidelines Contributor Guidelines] Retrieved January 28, 2014.</ref> Their digitization guidelinesGeorgia's collaborative digitization program, the Digital Library of Georgia, presents a seamless virtual library on the state's history and life, including more than a hundred digital collections from 60 institutions and 100 agencies of government. The [[Digital Library of Georgia]] is a GALILEO initiative based at the University of Georgia Libraries.<ref>Digital Library of Georgia, [http://dlg.galileo.usg.edu/?Welcome Welcome to the Digital Library of Georgia] Retrieved January 29, 2014.</ref>
  
 
==Advantages==
 
==Advantages==
 
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The advantages of digital libraries as a means of easily and rapidly accessing books, archives, and images of various types are now widely recognized by commercial interests and public bodies alike.<ref>Europa, [http://europa.eu/rapid/pressReleasesAction.do?reference=IP/06/253&type=HTML&aged=0&language=EN&guiLanguage=en European Commission steps up efforts to put Europe’s memory.] Retrieved June 6, 2008.</ref>  
The advantages of digital libraries as a means of easily and rapidly accessing books, archives and images of various types are now widely recognized by commercial interests and public bodies alike<ref>[http://europa.eu/rapid/pressReleasesAction.do?reference=IP/06/253&type=HTML&aged=0&language=EN&guiLanguage=en European Commission steps up efforts to put Europe’s memory] on the Web via a “European Digital Library” Europa press release, 2 March 2006. Retrieved June 6, 2008.</ref>.
 
  
 
Traditional libraries are limited by storage space; digital libraries have the potential to store much more information, simply because digital information requires very little physical space to contain it. As such, the cost of maintaining a digital library is much lower than that of a traditional library. A traditional library must spend large sums of money paying for staff, book maintenance such as repurchase of lost books, facilities, and additional facility maintenance fees. Digital libraries do away with some of these fees.
 
Traditional libraries are limited by storage space; digital libraries have the potential to store much more information, simply because digital information requires very little physical space to contain it. As such, the cost of maintaining a digital library is much lower than that of a traditional library. A traditional library must spend large sums of money paying for staff, book maintenance such as repurchase of lost books, facilities, and additional facility maintenance fees. Digital libraries do away with some of these fees.
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patrons of a library, due to geographic location or organizational affiliation.
 
patrons of a library, due to geographic location or organizational affiliation.
  
* '''No physical boundary'''. The user of a digital library need not to go to the library physically; people from all over the world can gain access to the same information, as long as an Internet connection is available.  
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* '''No physical boundary.''' The user of a digital library need not to go to the library physically; people from all over the world can gain access to the same information, as long as an Internet connection is available.  
* '''Round the clock availability'''. A major advantage of digital libraries is that people can gain access to the information at any time, night or day.  
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* '''Round the clock availability.''' A major advantage of digital libraries is that people can gain access to the information at any time, night or day.  
* '''Multiple access'''. The same resources can be used simultaneously by a number of institutions and patrons
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* '''Multiple access.''' The same resources can be used simultaneously by a number of institutions and patrons
* '''Information retrieval'''. The user is able to use any search term (word, phrase, title, name, subject) to search the entire collection. Digital libraries can provide very user-friendly interfaces, giving clickable access to its resources.  
+
* '''Information retrieval.''' The user is able to use any search term (word, phrase, title, name, subject) to search the entire collection. Digital libraries can provide very user-friendly interfaces, giving clickable access to its resources.  
* '''Preservation and conservation'''. Digitization is not a long-term preservation solution for physical collections, but does succeed in providing access copies for materials that would otherwise fall to degradation from repeated use. Digitized collections and born-digital objects pose many preservation and conservation concerns that analog materials do not. Please see the following "Problems" section of this page for examples.
+
* '''Preservation and conservation.''' Digitization is not a long-term preservation solution for physical collections, but does succeed in providing access copies for materials that would otherwise fall to degradation from repeated use. Digitized collections and born-digital objects pose many preservation and conservation concerns that analog materials do not. Please see the following "Problems" section of this page for examples.
* '''Space'''. Whereas traditional libraries are limited by storage space, digital libraries have the potential to store much more information, simply because digital information requires very little physical space to contain them and media storage technologies are more affordable than ever before.
+
* '''Space.''' Whereas traditional libraries are limited by storage space, digital libraries have the potential to store much more information, simply because digital information requires very little physical space to contain them and media storage technologies are more affordable than ever before.
* '''Added value'''. Certain characteristics of objects, primarily the quality of images, may be improved. Digitization can enhance legibility and remove visible flaws such as stains and discoloration.<ref>Gertz, Janet. "Selection for Preservation in the Digital Age." ''Library Resources & Technical Services.'' 44(2) (2000):97-104.</ref>
+
* '''Added value.''' Certain characteristics of objects, primarily the quality of images, may be improved. Digitization can enhance legibility and remove visible flaws such as stains and discoloration.<ref>Janet Gertz, Selection for Preservation in the Digital Age, ''Library Resources & Technical Services'' 44(2) (2000): 97-104.</ref>
  
 
==Problems==
 
==Problems==
===Changes of technologies===
+
===Developments in technology===
Technological standards change over time and forward data migration must be a constant consideration of every library. Data migration is a means of transferring an unstable digital object to another more stable format, operating system, or programming language.<ref>Cain, Mark. “Managing Technology: Being a Library of Record in a Digital Age,Journal of Academic Librarianship 29:6 (2003).</ref> Data migration allows the ability to retrieve and display digital objects that are in danger of becoming extinct. This is a rather successful short-term solution for the problem of aging and obsolete digital formats, but with the ever-changing nature of computer technologies, data migration becomes this never-ending race to transfer digital objects to new and more stable formats. Data migration is also flawed in the sense that when the digital files are being transferred, the new platform may not be able to capture the full integrity of the original object.<ref>Breeding, Marshall. “Preserving Digital Information..” Information Today 19:5 (2002).</ref> There are countless artifacts sitting in libraries all over the world that are essentially useless because the technology required to access the source is obsolete. In addition to obsolescence, there are rising costs that result from continually replacing the older technologies. This issue can dominate preservation policy and may put more focus on instant user access in place of physical preservation.<ref>Teper, Thomas H. "Where Next? Long-Term Considerations for Digital Initiatives." ''Kentucky Libraries'' 65(2)(2001):12-18.</ref>
+
Technological standards change over time and forward data migration must be a constant consideration of every library. Data migration is a means of transferring an unstable digital object to another more stable format, operating system, or programming language.<ref>Mark Cain, Managing Technology: Being a Library of Record in a Digital Age, ''Journal of Academic Librarianship'' 29:6 (2003).</ref> Data migration allows the ability to retrieve and display digital objects that are in danger of becoming extinct. This is a rather successful short-term solution for the problem of aging and obsolete digital formats, but with the ever-changing nature of computer technologies, data migration becomes this never-ending race to transfer digital objects to new and more stable formats. Data migration is also flawed in the sense that when the digital files are being transferred, the new platform may not be able to capture the full integrity of the original object.<ref>Marshall Breeding, Preserving Digital Information, ''Information Today'' 19:5 (2002).</ref> There are countless artifacts sitting in libraries all over the world that are essentially useless because the technology required to access the source is obsolete. In addition to obsolescence, there are rising costs that result from continually replacing the older technologies. This issue can dominate preservation policy and may put more focus on instant user access in place of physical preservation.<ref>Thomas H. Teper, Where Next? Long-Term Considerations for Digital Initiatives, ''Kentucky Libraries'' 65(2)(2001): 12-18.</ref>
  
 
===Copyrights===
 
===Copyrights===
Some people have criticized that digital libraries are hampered by [[copyright]] law, because works cannot be shared over different periods of time in the manner of a traditional library. There is a dilution of responsibility that occurs as a result of the spread-out nature of digital resources. Complex intellectual property matters may become involved since digital material isn't always owned by a library.<ref>Pymm, Bob. "Building Collections for All Time: The Issue of Significance." ''Australian Academic & Research Libraries.'' 37(1) (2006):61-73.</ref> The content is, in many cases, [[public domain]] or self-generated content only. Some digital libraries, such as [[Project Gutenberg]], work to digitize out-of-copyright works and make them freely available to the public.<ref name="nyt">{{cite news |first=Kevin |last=Kelly |authorlink= |coauthors= |title=Scan This Book! |url=http://www.nytimes.com/2006/05/14/magazine/14publishing.html?_r=1&oref=slogin&pagewanted=all |quote=When Google announced in December 2004 that it would digitally scan the books of five major research libraries to make their contents searchable, the promise of a universal library was resurrected. ... From the days of Sumerian clay tablets till now, humans have "published" at least 32 million books, 750 million articles and essays, 25 million songs, 500 million images, 500,000 movies, 3 million videos, TV shows and short films and 100 billion public Web pages.|publisher=[[New York Times Magazine]] |date=2006-05-14|accessdate=2008-03-07 }}</ref>  
+
Digital libraries are hampered by [[copyright]] law because, unlike with traditional printed works, the laws of digital copyright are still being formed. The republication of material on the web by libraries may require permission from rights holders, and there is a conflict of interest between libraries and the publishers who may wish to create online versions of their acquired content for commercial purposes. In 2010, it was estimated that twenty-three percent of books in existence were created before 1923 and thus out of copyright. Of those printed after this date, only five percent were still in print as of 2010. Thus, approximately seventy-two percent of books were not available to the public.<ref>Christopher Van Le, "Opening the Doors to Digital Libraries: A Proposal to Exempt Digital Libraries From the Copyright Act," ''Case Western Reserve Journal of Law, Technology & The Internet'', 1.2 (Spring 2010): 135.</ref>
 +
 
 +
There is a dilution of responsibility that occurs as a result of the distributed nature of digital resources. Complex [[intellectual property]] matters may become involved since digital material is not always owned by a library.<ref>Bob Pymm, "Building Collections for All Time: The Issue of Significance." ''Australian Academic & Research Libraries.'' 37(1) (2006):61-73.</ref> The content is, in many cases, [[public domain]] or self-generated content only. Some digital libraries, such as [[Project Gutenberg]], work to digitize out-of-copyright works and make them freely available to the public.<ref name="nyt">Kevin Kelly, [http://www.nytimes.com/2006/05/14/magazine/14publishing.html?_r=1&oref=slogin&pagewanted=all Scan This Book!] Retrieved March 7, 2008.</ref>
  
Other digital libraries accommodate copyright concerns by licensing content and distributing it on a commercial basis, which allows for better management of the content's reproduction and the payment (if required) of royalties. The [[Fair Use]] Provisions (17 USC § 107) under copyright law provide specific guidelines under which circumstances libraries are allowed to copy digital resources. Four factors that constitute fair use are purpose of use, nature of the work, market impact, and amount or substantiality used.<ref>[http://fairuse.stanford.edu/commentary_and_analysis/2003_11_hirtle.html Stanford Copyright & Fair Use - Digital Preservation and Copyright by Peter B. Hirtle]. Retrieved June 6, 2008.</ref>
+
The [[Fair Use]] Provisions (17 USC § 107) under copyright law provide specific guidelines under which circumstances libraries are allowed to copy digital resources. Four factors that constitute fair use are purpose of use, nature of the work, market impact, and amount or substantiality used.<ref>Peter B. Hirtle, [http://fairuse.stanford.edu/commentary_and_analysis/2003_11_hirtle.html Stanford Copyright & Fair Use—Digital Preservation and Copyright.] Retrieved June 6, 2008.</ref>
  
The ease of digital reproduction has pushed art institutions into a more conservative stance on the issue of intellectual property rights (much in the same vein as it did the music industry.) But to whom do what the J. Paul Getty Museum’s Kenneth Hamma labels “public-domain works of art” belong? Public domain works that are too old to be included in ongoing copyright protection, yet still remain out of the public’s view and also “of educators, and of the general milieu of creativity.
+
Some digital libraries acquire a license to lend their resources. This may involve the restriction of lending out only one copy at a time for each license, and applying a system of [[digital rights management]] for this purpose.
  
A museum’s decision to guard this information hinders research and halts digitization efforts. If the Internet fosters the free-exchange of ideas for the sake of educational access, then these assertions undermine the mission of the museum and more general of digitization. Still, some proponents of intellectual property claim that controlling ownership of public domain artwork generates revenue through licensing fees, and this accrued funding directly benefits institutional operation.
+
The [[Digital Millennium Copyright Act]] of 1998 was an act created in the United States to attempt to deal with the introduction of digital works. This Act incorporates two treaties from the year 1996. It criminalizes the attempt to circumvent measures which limit access to copyrighted materials. It also criminalizes the act of attempting to circumvent access control.<ref name=dmca>United States Copyright Office, [http://www.copyright.gov/legislation/dmca.pdf "The Digital Millennium Copyright Act of 1998 - U.S. Copyright Office Summary"] 1998, 2. Retrieved January 30, 2014.</ref>  This act provides an exemption for nonprofit libraries and archives which allows up to three copies to be made, one of which may be digital. This may not be made public or distributed on the web, however. Further, it allows libraries and archives to copy a work if its format becomes obsolete.<ref name=dmca/>
==See also==
 
*[[DELOS]] - European Network of Excellence on Digital Libraries
 
*[[Digital obsolescence]]
 
*[[Digital preservation]]
 
*[[Dynamic web page]]
 
*[[Electronic journal]]
 
*[[European Conference on Digital Libraries]]
 
*[[Google Books Library Project]]
 
*[[Internet Archive]]
 
*[[Library of Congress Digital Library project]]
 
*[[National Digital Information Infrastructure and Preservation Program]]
 
*[[National repository]]
 
*[[Open Content Alliance]]
 
*[[Project Gutenberg]]
 
*[[Repository (publishing)]]
 
*[[Storage Resource Broker]]
 
*[[Windows Live Search Books]]
 
*[[World Digital Library]]
 
  
 
== Notes==
 
== Notes==
{{Reflist|2}}
+
<references/>
 +
 
 
==References==
 
==References==
*Breeding, Marshall. “Preserving Digital Information..” ''Information Today'' 19:5 (2002).
+
*Breeding, Marshall. “Preserving Digital Information.” ''Information Today'' 19(5) (2002).
*Cain, Mark. “Managing Technology: Being a Library of Record in a Digital Age,” ''Journal of Academic Librarianship'' 29:6 (2003).
+
*Cain, Mark. “Managing Technology: Being a Library of Record in a Digital Age.” ''Journal of Academic Librarianship'' 29(6) (2003).
 
*De Stefano, Paula. "Selection for digital conversion in academic libraries." ''College & Research Libraries'' 62(1) (2001): 58-69.
 
*De Stefano, Paula. "Selection for digital conversion in academic libraries." ''College & Research Libraries'' 62(1) (2001): 58-69.
*Edward A. Fox. "The Digital Libraries Initiative - Update and Discussion," ''Bulletin of the America Society of Information Science'', Vol. 26, No 1, October/November (1999).  
+
*Fox, Edward A. "The Digital Libraries Initiative - Update and Discussion." ''Bulletin of the America Society of Information Science.'' 26(1).  
*Gertz, Janet. "Selection for Preservation in the Digital Age." Library Resources & Technical Services. 44(2) (2000): 97-104.
+
*Gertz, Janet. "Selection for Preservation in the Digital Age." ''Library Resources & Technical Services'' 44(2) (2000): 97-104.
*Greenstein, Daniel I., Thorin, Suzanne Elizabeth. ''The Digital Library: A Biography.'' Digital Library Federation, 2002. ISBN 1933645180.
+
*Greenstein, Daniel I., and Suzanne Elizabeth Thorin. ''The Digital Library: A Biography.'' Digital Library Federation, 2002.
*Hazen, Dan C., Jeffrey L. Horrell, and Jan Merrill-Oldham. ''Selecting Research Collections for Digitization: Economics of information.'' Washington, D.C.: Council on Library and Information Resources, 1998. ISBN 1887334602 ISBN 9781887334600.
+
*Hazen, Dan C., Jeffrey L. Horrell, and Jan Merrill-Oldham. ''Selecting Research Collections for Digitization: Economics of Information.'' Washington, D.C.: Council on Library and Information Resources, 1998. ISBN 1887334602
*Heritage Preservation. ''A Public Trust at Risk: The Heritage Health Index Report on the State of America’s Collections.'' Washington, D.C.: Heritage Preservation, 2005
+
*Heritage Preservation. ''A Public Trust at Risk: The Heritage Health Index Report on the State of America’s Collections.'' Washington, D.C.: Heritage Preservation, 2005.
*Koehler, AEC. "Some Thoughts on the Meaning of Open Access for University Library Technical Services," ''Serials Review'' Vol. 32, 1 (2006): 17
+
*Koehler, AEC. "Some Thoughts on the Meaning of Open Access for University Library Technical Services." ''Serials Review'' 32(1) (2006): 17
*Marcum, Deanna B. "Digitizing for Access and Preservation: Strategies of the Library of Congress," ''First Monday'', volume 12, number 7 (July 2007).  
+
*Marcum, Deanna B. "Digitizing for Access and Preservation: Strategies of the Library of Congress." ''First Monday'' 12(7).  
*Pymm, Bob. "Building Collections for All Time: The Issue of Significance." ''Australian Academic & Research Libraries.'' 37(1) (2006):61-73.
+
*Pymm, Bob. "Building Collections for All Time: The Issue of Significance." ''Australian Academic & Research Libraries.'' 37(1) (2006): 61-73.
*Silipigni Connaway, L, et. al. "Last copies: What's at risk?." ''College & Research Libraries,'' 67(4) (2006): 370-9.
+
*Silipigni Connaway, L., et al. "Last copies: What's at risk?" ''College & Research Libraries'' 67(4) (2006): 370-9.
 
*Teper, Thomas H. "Where Next? Long-Term Considerations for Digital Initiatives." ''Kentucky Libraries.'' 65(2) (2001): 12-18.
 
*Teper, Thomas H. "Where Next? Long-Term Considerations for Digital Initiatives." ''Kentucky Libraries.'' 65(2) (2001): 12-18.
  
 
==External links==
 
==External links==
All links retrieved June 7, 2008.
+
All links retrieved January 29, 2024.
*[http://www.llrx.com/features/digitization.htm Library Digitization Projects and Copyright - Part I - Introduction and Overview], by Mary Minow, LLRX.com (Law and technology resources for legal professionals), Published on June 28, 2002
+
 
 
*[http://www.diglib.org/ Digital Library Federation].
 
*[http://www.diglib.org/ Digital Library Federation].
*[http://digitalwa.statelib.wa.gov/newsite/best.htm Washington State Library: Digital Best Practices]
 
*[http://gutenberg.net/ Project Gutenberg]
 
 
*[http://www.archive.org/index.php Internet Archive]
 
*[http://www.archive.org/index.php Internet Archive]
 
*[http://vlib.org/ WWW Virtual Library]
 
*[http://vlib.org/ WWW Virtual Library]
 +
*[http://recollectionwisconsin.org Recollection Wisconsin]
  
 
[[Category:Library and information science]]
 
[[Category:Library and information science]]
 
+
[[Category:image wanted]]
 
{{credits|Digital_library|215603635|Google_Books_Library_Project|217338533}}
 
{{credits|Digital_library|215603635|Google_Books_Library_Project|217338533}}

Latest revision as of 14:37, 29 January 2024

A digital library is a library in which collections are stored in digital formats (as opposed to print, microform, or other media) and accessible by computers.[1] The digital content may be stored locally, or accessed remotely via computer networks. A digital library is a type of information retrieval system.

A digital library has a number of advantages and problems not found in a traditional library. Some of the advantages are that there are no physical limits to information storage, materials can be accessed around the clock by multiple users, and they feature efficient information retrieval mechanisms. Some of the problems unique to a digital library include the need for periodical data migration due to constant and rapid technological advancement of information technology, as well as issues concerning copyright infringement. Nevertheless, library and information professional communities are pursuing a workable model of a digital library and a number of initiatives have been made both in the public and private sectors. For example, Google collaborated with a number of major academic libraries and made a large number of library holdings available to internet users under the Google Books Library Project.

Terminology

The first use of the term "digital library" in print may have been in a 1988 report to the Corporation for National Research Initiatives[2] The term "digital libraries" was first popularized by the NSF/DARPA/NASA Digital Libraries Initiative in 1994.[3] The older names electronic library or virtual library are also occasionally used, though "electronic library" nowadays more often refers to portals, often provided by government agencies, as in the case of the Florida Electronic Library.[4]

Types of digital libraries

The term "digital library" is diffuse enough to be applied to a wide range of collections and organizations, but to be considered a digital library an online collection of information must be managed by and made accessible to a community of users. Thus, only some web sites can be considered true digital libraries. Many of the best known digital libraries are older than the Web including Project Perseus, Project Gutenberg, and ibiblio. Nevertheless, as a result of the development of the internet and its search potential, digital libraries such as the European Library and the Library of Congress are now developing in a Web-based environment. Public, school and college libraries are also able to develop digital download websites, featuring eBooks, audiobooks, music and video, through companies like OverDrive, Inc.

A distinction is often made between content that was created in a digital format, known as born-digital, and information that has been converted from a physical medium, for example, paper, by digitizing. The term "hybrid library" is sometimes used for libraries that have both physical collections and digital collections. They consist of a combination of traditional preservation efforts such as microfilming and new technologies involving digital projects. For example, American Memory is a digital library within the Library of Congress. Some important digital libraries also serve as long term archives, for example, the ePrint, arXiv, and the Internet Archive.

Academic repositories

Many academic libraries are actively involved in building institutional repositories of the institution's books, papers, theses, and other works which can be digitized or were "born digital." Many of these repositories are made available to the general public with few restrictions, in accordance with the goals of open access. Institutional, truly free, and corporate repositories are often referred to as digital libraries.

Digital archives

Archives differ from libraries in several ways. Traditionally, archives were defined as:

  1. Containing primary sources of information (typically letters and papers directly produced by an individual or organization) rather than the secondary sources found in a library (books, papers, journals, and so on)
  2. Having their contents organized in groups rather than individual items. Whereas books in a library are cataloged individually, items in an archive are typically grouped by provenance (the individual or organization who created them) and original order (the order in which the materials were kept by the creator)
  3. Having unique contents. Whereas a book may be found at many different libraries, depending on its rarity, the records in an archive are usually one-of-a-kind, and cannot be found or consulted at any other location except at the archive that holds them

The technology used to create digital libraries has been even more revolutionary for archives. since it breaks down the second and third of these general rules. The use of search engines, Optical Character Recognition, and metadata allow digital copies of individual items (such as letters) to be cataloged, and the ability to remotely access digital copies has removed the necessity of physically going to a particular archive to find a particular set of records. The Oxford Text Archive is generally considered to be the oldest digital archive of academic primary source materials.

Project Gutenberg, Google Book Search, Windows Live Search Books, Internet Archive, Cornell University, the Library of Congress World Digital Library, the Digital Library at the University of Michigan, and CMU's Universal library are considered leaders in the field of digital archive creation and management. There are hundreds of regional digital archives, such as the Wisconsin Historical Society. The Vatican maintains an extensive digital library inventory and associated technology. The entire works of Martin Luther are held at Emory University and are being digitized under an $8M Grant from Coca-Cola heirs, and the Packard Foundation maintains digitization facilities near the Acropolis in Athens, Greece.

The future

Large scale digitization projects are underway at Google, the Million Book Project, MSN, and Yahoo! With continued improvements in book handling and presentation technologies, such as optical character recognition and ebooks, and development of alternative depositories and business models, digital libraries are rapidly growing in popularity as demonstrated by Google, Yahoo!, and MSN's efforts. Just as libraries have ventured into audio and video collections, so too have digital libraries, such as the Internet Archive.

Search mechanism

Most digital libraries provide a search interface which allows resources to be found. These resources are typically deep Web (or invisible Web) resources since they frequently cannot be located by search engine crawlers. Some digital libraries create special pages or sitemaps to allow search engines to find all their resources. Digital libraries frequently use the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) to expose their metadata to other digital libraries, and search engines like Google Scholar, Google, Yahoo! and Scirus can also use OAI-PMH to find these deep web resources.[5]

There are two general strategies for searching a federation of digital libraries:

  1. Distributed searching
  2. Searching previously harvested metadata.

Distributed searching typically involves a client sending multiple search requests in parallel to a number of servers in the federation. The results are gathered, duplicates are eliminated or clustered, and the remaining items are sorted and presented back to the client. Protocols like Z39.50 are frequently used in distributed searching. A benefit to this approach is that the resource-intensive tasks of indexing and storage are left to the respective servers in the federation. A drawback to this approach is that the search mechanism is limited by the different indexing and ranking capabilities of each database, making it difficult to assemble a combined result consisting of the most relevant found items.

Searching over previously harvested metadata involves searching a locally stored index of information that has previously been collected from the libraries in the federation. When a search is performed, the search mechanism does not need to make connections with the digital libraries it is searching—it already has a local representation of the information. This approach requires the creation of an indexing and harvesting mechanism which operates regularly, connecting to all the digital libraries and querying the whole collection in order to discover new and updated resources. OAI-PMH is frequently used by digital libraries for allowing metadata to be harvested. A benefit to this approach is that the search mechanism has full control over indexing and ranking algorithms, possibly allowing more consistent results. A drawback is that harvesting and indexing systems are more resource-intensive and therefore expensive.

Construction and organization

Frameworks

A digital library can be built around specific repository software. The best known examples of this are DSpace, Eprints, Fedora, dLibra, and Greenstone Digital Library Software.

Selection Criteria

A strategy with defined selection priorities for digitization is critical and should be informed by a convergence in the consideration for both preservation and access. The focus should be based on traditional preservation decisions such as the value of materials; the condition of materials; use of materials; and material characteristics ensuring a high level of success. For the Library of Congress, for example, items of national interest are prime candidates and digitizing these objects improves access while reducing the wear and tear on the originals.[6]

In the early discussions about digitization of library materials, the selection decisions were proposed based on a desire for better access to that item's content and not on the condition or value of the original item.[7] In 2001, Paula De Stefano[8]wrote that a use-based criteria was promising, as it is “fundamental to collection development and is the common thread in all selection decisions” however her own study showed that use was not the most popular approach—in fact, most digital projects at the time focused on special collections, which are generally not the most popular items in the overall collection.

The persistent risk of disappearing "last copies"[9] and the declines seen in the condition of national treasures, as exemplified by the 2005 Heritage Health Index Report on the State of America's Collections[10] provide the rationale for establishing priorities and balancing access with preservation needs. The transient nature of electronic information can contribute to a phenomenon called "memory loss." This is a result of data extinctions as technologies become obsolete. There is also a drift away from original bibliographic contexts as time passes.[11] A 1998 Council on Library and Information Sources white paper[12] identified the following comprehensive considerations for selection: Assessment of the intellectual and physical nature of the source materials; the number and location of current and potential users; the current and potential nature of use; the format and nature of the proposed digital product and how it will be described, delivered, and archived; how the proposed product relates to other digitization efforts; and projections of costs in relation to benefits.

Digitization

Digitization is the process of representing an object, an image, or a signal (usually an analog signal) by a discrete set of its points or samples. The result is called "digital representation" or, more specifically, a "digital image," for the object, and "digital form," for the signal.

Analog signals are continuously variable, both in the number of possible values of the signal at a given time, as well as in the number of points in the signal in a given period of time. However, digital signals are discrete in both of those respects, and so a digitization can only ever be an approximation of the signal it represents. The digital representation does not necessarily lose information in this transformation since the analog signal usually contains both information and noise.

A digital signal may be represented by a sequence of integers. Digitization is performed by reading an analog signal, A, and, at regular time intervals (sampling frequency), representing the value of A at that point by an integer. Each such reading is called a sample.

A series of integers can be transformed back into an analog signal that approximates the original analog signal. Such a transformation is called DA conversion. There are two factors determining how close such an approximation to an analog signal A a digitization D can be, namely the sampling rate and the number of bits used to represent the integers.

In the past few years, procedures for digitizing books at high speed and comparatively low cost have improved considerably with the result that it is now possible to plan the digitization of millions of books per year for creating digital libraries.[13]

Collaborative digitization projects

There are many collaborative digitization projects throughout the United States and in Europe, Australia, and Asia. Two of the earliest projects were the Collaborative Digitization Project, in Colorado, and NC ECHO, North Carolina Exploring Cultural Heritage Online, based at the State Library of North Carolina. These projects helped to establish and publish best practices for digitization and work with regional partners to digitize cultural heritage materials. Additional criteria for best practice have more recently been established in the UK, Australia, and the European Union.[14] Recollection Wisconsin, formerly Wisconsin Heritage Online, is a collaborative digitization project modeled after the Colorado Collaborative Digitization Project. They collaborate with libraries, archives, historical societies, and museums across Wisconsin to facilitate digitization efforts.[15] Their digitization guidelinesGeorgia's collaborative digitization program, the Digital Library of Georgia, presents a seamless virtual library on the state's history and life, including more than a hundred digital collections from 60 institutions and 100 agencies of government. The Digital Library of Georgia is a GALILEO initiative based at the University of Georgia Libraries.[16]

Advantages

The advantages of digital libraries as a means of easily and rapidly accessing books, archives, and images of various types are now widely recognized by commercial interests and public bodies alike.[17]

Traditional libraries are limited by storage space; digital libraries have the potential to store much more information, simply because digital information requires very little physical space to contain it. As such, the cost of maintaining a digital library is much lower than that of a traditional library. A traditional library must spend large sums of money paying for staff, book maintenance such as repurchase of lost books, facilities, and additional facility maintenance fees. Digital libraries do away with some of these fees.

Digital libraries can immediately adopt innovations in technology providing users with improvements in electronic and audio book technology as well as presenting new forms of communication such as wikis and blogs. An important advantage to digital conversion is increased accessibility to users and availability for individuals who may not be traditional patrons of a library, due to geographic location or organizational affiliation.

  • No physical boundary. The user of a digital library need not to go to the library physically; people from all over the world can gain access to the same information, as long as an Internet connection is available.
  • Round the clock availability. A major advantage of digital libraries is that people can gain access to the information at any time, night or day.
  • Multiple access. The same resources can be used simultaneously by a number of institutions and patrons
  • Information retrieval. The user is able to use any search term (word, phrase, title, name, subject) to search the entire collection. Digital libraries can provide very user-friendly interfaces, giving clickable access to its resources.
  • Preservation and conservation. Digitization is not a long-term preservation solution for physical collections, but does succeed in providing access copies for materials that would otherwise fall to degradation from repeated use. Digitized collections and born-digital objects pose many preservation and conservation concerns that analog materials do not. Please see the following "Problems" section of this page for examples.
  • Space. Whereas traditional libraries are limited by storage space, digital libraries have the potential to store much more information, simply because digital information requires very little physical space to contain them and media storage technologies are more affordable than ever before.
  • Added value. Certain characteristics of objects, primarily the quality of images, may be improved. Digitization can enhance legibility and remove visible flaws such as stains and discoloration.[18]

Problems

Developments in technology

Technological standards change over time and forward data migration must be a constant consideration of every library. Data migration is a means of transferring an unstable digital object to another more stable format, operating system, or programming language.[19] Data migration allows the ability to retrieve and display digital objects that are in danger of becoming extinct. This is a rather successful short-term solution for the problem of aging and obsolete digital formats, but with the ever-changing nature of computer technologies, data migration becomes this never-ending race to transfer digital objects to new and more stable formats. Data migration is also flawed in the sense that when the digital files are being transferred, the new platform may not be able to capture the full integrity of the original object.[20] There are countless artifacts sitting in libraries all over the world that are essentially useless because the technology required to access the source is obsolete. In addition to obsolescence, there are rising costs that result from continually replacing the older technologies. This issue can dominate preservation policy and may put more focus on instant user access in place of physical preservation.[21]

Copyrights

Digital libraries are hampered by copyright law because, unlike with traditional printed works, the laws of digital copyright are still being formed. The republication of material on the web by libraries may require permission from rights holders, and there is a conflict of interest between libraries and the publishers who may wish to create online versions of their acquired content for commercial purposes. In 2010, it was estimated that twenty-three percent of books in existence were created before 1923 and thus out of copyright. Of those printed after this date, only five percent were still in print as of 2010. Thus, approximately seventy-two percent of books were not available to the public.[22]

There is a dilution of responsibility that occurs as a result of the distributed nature of digital resources. Complex intellectual property matters may become involved since digital material is not always owned by a library.[23] The content is, in many cases, public domain or self-generated content only. Some digital libraries, such as Project Gutenberg, work to digitize out-of-copyright works and make them freely available to the public.[24]

The Fair Use Provisions (17 USC § 107) under copyright law provide specific guidelines under which circumstances libraries are allowed to copy digital resources. Four factors that constitute fair use are purpose of use, nature of the work, market impact, and amount or substantiality used.[25]

Some digital libraries acquire a license to lend their resources. This may involve the restriction of lending out only one copy at a time for each license, and applying a system of digital rights management for this purpose.

The Digital Millennium Copyright Act of 1998 was an act created in the United States to attempt to deal with the introduction of digital works. This Act incorporates two treaties from the year 1996. It criminalizes the attempt to circumvent measures which limit access to copyrighted materials. It also criminalizes the act of attempting to circumvent access control.[26] This act provides an exemption for nonprofit libraries and archives which allows up to three copies to be made, one of which may be digital. This may not be made public or distributed on the web, however. Further, it allows libraries and archives to copy a work if its format becomes obsolete.[26]

Notes

  1. Daniel I. Greenstein and Suzanne Elizabeth Thorin, The Digital Library: A Biography, Digital Library Federation (2002). ISBN 1933645180. Retrieved June 25, 2007.
  2. R.E. Kahn and V.G. Cerf The Digital Library Project Volume I: The World of Knowbots, (DRAFT): An Open Architecture For a Digital Library System and a Plan For Its Development. Retrieved June 6, 2008.
  3. Edward A. Fox. The Digital Libraries Initiative—Update and Discussion, Bulletin of the America Society of Information Science, Vol. 26, No 1, October/November 1999. Retrieved June 6, 2008.
  4. Florida Electronic Library, About Us. Retrieved January 29, 2014.
  5. AEC Koehler, Some Thoughts on the Meaning of Open Access for University Library Technical Services Serials Review Vol. 32, 1, 2006, p. 17.
  6. Deanna B. Marcum, Digitizing for Access and Preservation: Strategies of the Library of Congress, First Monday, volume 12, number 7 (July 2007). Retrieved June 6, 2008.
  7. J. Gertz, Selection for preservation in the digital age: An overview, Library Resources & Technical Services 44(2): 97-104.
  8. Paula De Stefano, Selection for digital conversion in academic libraries, College & Research Libraries 62(1): 58-69.
  9. L. Silipigni Connaway, et al., Last copies: What's at risk? College & Research Libraries, 67(4): 370-9.
  10. Heritage Preservation, A Public Trust at Risk: The Heritage Health Index Report on the State of America’s Collections (Washington, D.C.: Heritage Preservation).
  11. Thomas H. Teper, "Where Next? Long-Term Considerations for Digital Initiatives," Kentucky Libraries 65(2) (2001): 12-18.
  12. Dan C. Hazen, Jeffrey L. Horrell, and Jan Merrill-Oldham, Selecting Research Collections for Digitization, Economics of information (Washington, D.C.: Council on Library and Information Resources, 1998, ISBN 1887334602). Retrieved June 6, 2008.
  13. Committee on Institutional Cooperation, Partnership announced between CIC and Google.
  14. Ariadne, Digital Libraries: Principles and Practice in a Global Environment. Retrieved June 6, 2008.
  15. Recollection Wisconsin, Contributor Guidelines Retrieved January 28, 2014.
  16. Digital Library of Georgia, Welcome to the Digital Library of Georgia Retrieved January 29, 2014.
  17. Europa, European Commission steps up efforts to put Europe’s memory. Retrieved June 6, 2008.
  18. Janet Gertz, Selection for Preservation in the Digital Age, Library Resources & Technical Services 44(2) (2000): 97-104.
  19. Mark Cain, Managing Technology: Being a Library of Record in a Digital Age, Journal of Academic Librarianship 29:6 (2003).
  20. Marshall Breeding, Preserving Digital Information, Information Today 19:5 (2002).
  21. Thomas H. Teper, Where Next? Long-Term Considerations for Digital Initiatives, Kentucky Libraries 65(2)(2001): 12-18.
  22. Christopher Van Le, "Opening the Doors to Digital Libraries: A Proposal to Exempt Digital Libraries From the Copyright Act," Case Western Reserve Journal of Law, Technology & The Internet, 1.2 (Spring 2010): 135.
  23. Bob Pymm, "Building Collections for All Time: The Issue of Significance." Australian Academic & Research Libraries. 37(1) (2006):61-73.
  24. Kevin Kelly, Scan This Book! Retrieved March 7, 2008.
  25. Peter B. Hirtle, Stanford Copyright & Fair Use—Digital Preservation and Copyright. Retrieved June 6, 2008.
  26. 26.0 26.1 United States Copyright Office, "The Digital Millennium Copyright Act of 1998 - U.S. Copyright Office Summary" 1998, 2. Retrieved January 30, 2014.

References
ISBN links support NWE through referral fees

  • Breeding, Marshall. “Preserving Digital Information.” Information Today 19(5) (2002).
  • Cain, Mark. “Managing Technology: Being a Library of Record in a Digital Age.” Journal of Academic Librarianship 29(6) (2003).
  • De Stefano, Paula. "Selection for digital conversion in academic libraries." College & Research Libraries 62(1) (2001): 58-69.
  • Fox, Edward A. "The Digital Libraries Initiative - Update and Discussion." Bulletin of the America Society of Information Science. 26(1).
  • Gertz, Janet. "Selection for Preservation in the Digital Age." Library Resources & Technical Services 44(2) (2000): 97-104.
  • Greenstein, Daniel I., and Suzanne Elizabeth Thorin. The Digital Library: A Biography. Digital Library Federation, 2002.
  • Hazen, Dan C., Jeffrey L. Horrell, and Jan Merrill-Oldham. Selecting Research Collections for Digitization: Economics of Information. Washington, D.C.: Council on Library and Information Resources, 1998. ISBN 1887334602
  • Heritage Preservation. A Public Trust at Risk: The Heritage Health Index Report on the State of America’s Collections. Washington, D.C.: Heritage Preservation, 2005.
  • Koehler, AEC. "Some Thoughts on the Meaning of Open Access for University Library Technical Services." Serials Review 32(1) (2006): 17
  • Marcum, Deanna B. "Digitizing for Access and Preservation: Strategies of the Library of Congress." First Monday 12(7).
  • Pymm, Bob. "Building Collections for All Time: The Issue of Significance." Australian Academic & Research Libraries. 37(1) (2006): 61-73.
  • Silipigni Connaway, L., et al. "Last copies: What's at risk?" College & Research Libraries 67(4) (2006): 370-9.
  • Teper, Thomas H. "Where Next? Long-Term Considerations for Digital Initiatives." Kentucky Libraries. 65(2) (2001): 12-18.

External links

All links retrieved January 29, 2024.

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