Editing Digital preservation (section)

==Fundamentals==

===Appraisal===
[[Archival appraisal]] (or, alternatively, selection<ref>{{cite web|title=Society of American Archivists Glossary - selection |work=web site |year=2014 |url=http://www2.archivists.org/glossary/terms/s/selection |access-date=8 October 2014 |url-status=live |archive-url=https://web.archive.org/web/20141012221022/http://www2.archivists.org/glossary/terms/s/selection |archive-date=12 October 2014 }}</ref>) refers to the process of identifying records and other materials to be preserved by determining their permanent value. Several factors are usually considered when making this decision.<ref>{{cite web|title=Society of American Archivists Glossary - appraisal |work=web site |year=2014 |url=http://www2.archivists.org/glossary/terms/a/appraisal |access-date=8 October 2014 |url-status=live |archive-url=https://web.archive.org/web/20141012221148/http://www2.archivists.org/glossary/terms/a/appraisal |archive-date=12 October 2014 }}</ref> It is a difficult and critical process because the remaining selected records will shape researchers' understanding of that body of records, or [[fonds]]. Appraisal is identified as A4.2 within the Chain of Preservation (COP) model<ref>{{cite web|title=InterPARES 2 Chain of Preservation Model |work=web site |year=2007 |url=http://www.interpares.org/ip2/ip2_model_display.cfm?model=cop |access-date=8 October 2014 |url-status=live |archive-url=https://web.archive.org/web/20150924035605/http://www.interpares.org/ip2/ip2_model_display.cfm?model=cop |archive-date=24 September 2015 }}</ref> created by the InterPARES 2 project.<ref>{{cite web|title=InterPARES 2 Project |work=web site |url=http://www.interpares.org/ip2/ip2_products.cfm |access-date=8 October 2014 |url-status=live |archive-url=https://web.archive.org/web/20141002192640/http://www.interpares.org/ip2/ip2_products.cfm |archive-date=2 October 2014 }}</ref> Archival appraisal is not the same as monetary appraisal, which determines [[fair market value]].

Archival appraisal may be performed once or at the various stages of acquisition and [[archival processing|processing]]. Macro appraisal,<ref>{{cite web|title=Society of American Archivists Glossary - macro-appraisal |work=web site |year=2014 |url=http://www2.archivists.org/glossary/terms/m/macro-appraisal |access-date=8 October 2014 |url-status=live |archive-url=https://web.archive.org/web/20141012221236/http://www2.archivists.org/glossary/terms/m/macro-appraisal |archive-date=12 October 2014 }}</ref> a functional analysis of records at a high level, may be performed even before the records have been acquired to determine which records to acquire. More detailed, iterative appraisal may be performed while the records are being processed.

Appraisal is performed on all archival materials, not just digital. It has been proposed that, in the digital context, it might be desirable to retain more records than have traditionally been retained after appraisal of analog records, primarily due to a combination of the declining cost of storage and the availability of sophisticated discovery tools which will allow researchers to find value in records of low information density.<ref>{{cite journal
 |author-link=Courtney C. Mumma, Glenn Dingwall, Sue Bigelow 
 |title=A First Look at the Acquisition and Appraisal of the 2010 Olympic and Paralympic Winter Games Fonds: or, SELECT * FROM VANOC_Records AS Archives WHERE Value="true"; 
 |journal=Archivaria 
 |volume=72 
 |issue=72 
 |pages=114–117 
 |date=2011 
 |url=http://journals.sfu.ca/archivar/index.php/archivaria/article/view/13361/14666 
 |issn=1923-6409 
 |access-date=October 8, 2014 
 |url-status=live 
 |archive-url=https://web.archive.org/web/20141013135211/http://journals.sfu.ca/archivar/index.php/archivaria/article/view/13361/14666 
 |archive-date=October 13, 2014 
|last1=Bigelow 
 |first1=Sue 
 |last2=Dingwall 
 |first2=Glenn 
 |last3=Mumma 
 |first3=Courtney C. 
 }}</ref><ref>{{cite web|title=Paradigm (Personal Archives Accessible in Digital Media): Appraising digital records: a worthwhile exercise? |work=web site |year=2008 |url=http://www.paradigm.ac.uk/workbook/appraisal/digital-appraisal.html |access-date=8 October 2014 |url-status=live |archive-url=https://web.archive.org/web/20150201072749/http://www.paradigm.ac.uk/workbook/appraisal/digital-appraisal.html |archive-date=1 February 2015 }}</ref> In the analog context, these records may have been discarded or only a representative sample kept. However, the selection, appraisal, and prioritization of materials must be carefully considered in relation to the ability of an organization to responsibly manage the totality of these materials.

Often libraries, and to a lesser extent, archives, are offered the same materials in several different digital or analog formats. They prefer to select the format that they feel has the greatest potential for long-term preservation of the content. The [[Library of Congress]] has created a set of recommended formats for long-term preservation.<ref>{{cite web|title=Library of Congress Recommended Format Specifications |work=web site |year=2014 |url=https://www.loc.gov/preservation/resources/rfs/ |access-date=8 October 2014 |url-status=live |archive-url=https://web.archive.org/web/20141014175635/http://www.loc.gov/preservation/resources/rfs/ |archive-date=14 October 2014 }}</ref> They would be used, for example, if the Library was offered items for copyright deposit directly from a publisher.

===Identification (identifiers and descriptive metadata)===
In digital preservation and [[Collections management|collection management]], discovery and identification of objects is aided by the use of assigned identifiers and accurate descriptive metadata. An [[identifier]] is a unique label that is used to reference an object or record, usually manifested as a number or string of numbers and letters. As a crucial element of [[metadata]] to be included in a database record or inventory, it is used in tandem with other descriptive metadata to differentiate objects and their various instantiations.<ref name="niso.org">Greenberg, Jane. "[http://www.niso.org/publications/press/UnderstandingMetadata.pdf Understanding Metadata and Metadata Schemes] {{webarchive|url=https://web.archive.org/web/20141107022958/http://www.niso.org/publications/press/UnderstandingMetadata.pdf |date=2014-11-07 }}." Cataloging & Classification Quarterly 40.3-4 (2005): 17-36. National Information Standards Organization.</ref>

Descriptive metadata refers to information about an object's content such as title, creator, subject, date etc...<ref name="niso.org"/> Determination of the elements used to describe an object are facilitated by the use of a metadata schema. Extensive descriptive metadata about a digital object helps to minimize the risks of a digital object becoming inaccessible.<ref>{{Cite journal|last1=McDonough|first1=Jerome|last2=Jimenez|first2=Mona|year=2006|title=Video Preservation and Digital Reformatting: Pain and Possibility.|journal=Journal of Archival Organization |volume=4|issue=1–2|pages=167–191|doi=10.1300/J201v04n01_09|s2cid=62181844}}</ref>

Another common type of file identification is the [[filename]]. Implementing a file naming protocol is essential to maintaining consistency and efficient discovery and retrieval of objects in a collection, and is especially applicable during digitization of analog media. Using a file naming convention, such as the [[8.3 filename]] or the [[Standard (warez)|Warez standard naming]], will ensure compatibility with other systems and facilitate migration of data, and deciding between descriptive (containing descriptive words and numbers) and non-descriptive (often randomly generated numbers) file names is generally determined by the size and scope of a given collection.<ref>[http://www.jiscdigitalmedia.ac.uk/managing "Managing"] {{webarchive|url=https://web.archive.org/web/20141013234403/http://www.jiscdigitalmedia.ac.uk/managing |date=2014-10-13 }}. Jisc Digital Media. 08 Oct. 2014.</ref> However, filenames are not good for semantic identification, because they are non-permanent labels for a specific location on a system and can be modified without affecting the bit-level profile of a digital file.

===Integrity===
The cornerstone of digital preservation, "[[data integrity]]" refers to the assurance that the data is "complete and unaltered in all essential respects"; a program designed to maintain integrity aims to "ensure data is recorded exactly as intended, and upon later retrieval, ensure the data is the same as it was when it was originally recorded".<ref>{{cite web |url=https://www.cessda.eu/Tools-Services/For-Service-Providers/CESSDA-CDM/Glossary |title=Glossary |website=Consortium of European Social Science Data Archives |access-date=March 28, 2022}}</ref>

Unintentional changes to data are to be avoided, and responsible strategies should be put in place to detect unintentional changes and react as appropriately determined. However, digital preservation efforts may necessitate modifications to content or metadata through responsibly-developed procedures and by well-documented policies. Organizations or individuals may choose to retain original, integrity-checked versions of content and/or modified versions with appropriate preservation metadata. Data integrity practices also apply to modified versions, as their state of capture must be maintained and resistant to unintentional modifications.

The integrity of a record can be preserved through bit-level preservation, fixity checking, and capturing a full audit trail of all preservation actions performed on the record. These strategies can ensure protection against unauthorised or accidental alteration.<ref>{{Cite web |title=Digital Preservation Policy |url=https://www.naa.gov.au/about-us/our-organisation/accountability-and-reporting/archival-policy-and-planning/digital-preservation-policy |date=June 30, 2020 |website=National Archives of Australia |access-date=March 28, 2022}}</ref>

====Fixity====
[[File fixity]] is the property of a digital file being fixed, or unchanged. File fixity checking is the process of validating that a file has not changed or been altered from a previous state.<ref>{{cite web|url=https://www.loc.gov/standards/premis/pif-presentations/rebecca-SKOS/preservationEvents-FixityCheck.html |title=Preservation Events Concept: fixity check |work=loc.gov |url-status=live |archive-url=https://web.archive.org/web/20141014155135/http://www.loc.gov/standards/premis/pif-presentations/rebecca-SKOS/preservationEvents-FixityCheck.html |archive-date=2014-10-14 }}</ref> This effort is often enabled by the creation, validation, and management of [[checksum]]s.

While checksums are the primary mechanism for monitoring fixity at the individual file level, an important additional consideration for monitoring fixity is file attendance. Whereas checksums identify if a file has changed, file attendance identifies if a file in a designated collection is newly created, deleted, or moved. Tracking and reporting on file attendance is a fundamental component of digital collection management and fixity.

===Characterization===
Characterization of digital materials is the identification and description of what a file is and of its defining technical characteristics<ref>[http://www.openplanetsfoundation.org/system/files/Digital%20Preservation%20Project%20Report%20-%20Testing%20Software%20Tools.pdf Testing Software Tools of Potential Interest for Digital Preservation Activities at the National Library of Australia] {{webarchive|url=https://web.archive.org/web/20130114111844/http://www.openplanetsfoundation.org/system/files/Digital%20Preservation%20Project%20Report%20-%20Testing%20Software%20Tools.pdf |date=2013-01-14 }}</ref> often captured by technical metadata, which records its technical attributes like creation or production environment.<ref>{{cite web|url=http://www.library.illinois.edu/dcc/bestpractices/chapter_10_technicalmetadata.html |title=10.0 Best Practices for Technical Metadata |work=illinois.edu |url-status=live |archive-url=https://web.archive.org/web/20141009081725/http://www.library.illinois.edu/dcc/bestpractices/chapter_10_technicalmetadata.html |archive-date=2014-10-09 }}</ref>

===Sustainability===
Digital sustainability encompasses a range of issues and concerns that contribute to the longevity of digital information.<ref>Bradley, K. (Summer 2007). Defining digital sustainability. Library Trends v. 56 no 1 p. 148-163.</ref> Unlike traditional, temporary strategies, and more permanent solutions, digital sustainability implies a more active and continuous process. Digital sustainability concentrates less on the solution and technology and more on building an infrastructure and approach that is flexible with an emphasis on [[interoperability]], continued maintenance and continuous development.<ref>[http://www.tasi.ac.uk/advice/managing/sust.html Sustainability of Digital Resources. (2008). ''TASI: Technical Advisory Service for Images.'']  {{webarchive |url=https://web.archive.org/web/20080304023605/http://www.tasi.ac.uk/advice/managing/sust.html |date=March 4, 2008 }}</ref> Digital sustainability incorporates activities in the present that will facilitate access and availability in the future.<ref>[http://ijdc.net/index.php/ijdc/article/view/63 Towards a Theory of Digital Preservation. (2008). ''International Journal of Digital Curation''] {{webarchive|url=https://web.archive.org/web/20130123060816/http://www.ijdc.net/index.php/ijdc/article/view/63 |date=2013-01-23 }}</ref><ref>[http://wiki.lib.sun.ac.za/index.php/SUNScholar/Digital_Preservation/Electronic_Archives_Preservation_Policy ''Electronic Archives Preservation Policy'']  {{webarchive |url=https://web.archive.org/web/20130310105710/http://wiki.lib.sun.ac.za/index.php/SUNScholar/Digital_Preservation/Electronic_Archives_Preservation_Policy |date=March 10, 2013 }}</ref> The ongoing maintenance necessary to digital preservation is analogous to the successful, centuries-old, community upkeep of the [[Uffington White Horse]] (according to [[Stuart M. Shieber]]) or the [[Ise Grand Shrine#Rebuilding the Shrine|Ise Grand Shrine]] (according to [[Jeffrey Schnapp]]).<ref name="SchnappBattles2014">{{cite book|author1=Jeffrey Schnapp|author2=Matthew Battles|title=Library Beyond the Book |year= 2014|publisher=Harvard University Press|isbn=978-0-674-72503-4 |pages=66–68|title-link=Library Beyond the Book|author1-link=Jeffrey Schnapp}}</ref><ref>{{cite web|url=http://blogs.law.harvard.edu/pamphlet/2011/04/18/the-scouring-of-the-white-horse/ |author=Stuart Shieber |title=Scouring of the White Horse |work=Occasional Pamphlet (blog) |publisher=Harvard University |date=April 2011 |url-status=live |archive-url=https://web.archive.org/web/20141007063906/http://blogs.law.harvard.edu/pamphlet/2011/04/18/the-scouring-of-the-white-horse/ |archive-date=2014-10-07 }}</ref>

====Renderability====

Renderability refers to the continued ability to use and access a digital object while maintaining its inherent significant properties.<ref>{{cite web|url=http://www.dlib.org/dlib/september12/vermaaten/09vermaaten.html |title=Identifying Threats to Successful Digital Preservation: the SPOT Model for Risk Assessment |work=dlib.org |url-status=live |archive-url=https://web.archive.org/web/20150110194245/http://www.dlib.org/dlib/september12/vermaaten/09vermaaten.html |archive-date=2015-01-10 }}</ref>

====Physical media obsolescence====
[[Digital obsolescence|Physical media obsolescence]] can occur when access to digital content requires external dependencies that are no longer manufactured, maintained, or supported. External dependencies can refer to [[Digital obsolescence#Types of digital obsolescence|hardware, software, or physical carriers.]] For example, [[Digital Linear Tape|DLT tape]] was used for backups and data preservation, but is no longer used.

====Format obsolescence====
File format obsolescence can occur when adoption of new encoding formats supersedes use of existing formats, or when associated presentation tools are no longer readily available.<ref>{{cite journal|url=http://www.ijdc.net/index.php/ijdc/article/view/76/44 |title=  Defining File Format Obsolescence: A Risky Journey|date=6 August 2008 |volume=3 |issue=1 |pages=89–106 |doi=10.2218/ijdc.v3i1.44 |url-status=live |archive-url=https://web.archive.org/web/20141014030726/http://www.ijdc.net/index.php/ijdc/article/view/76/44 |archive-date=2014-10-14 |last1=Pearson |first1=David |last2=Webb |first2=Colin |journal= International Journal of Digital Curation|doi-access=free |hdl=1885/47621 |hdl-access=free }}</ref>

While the use of file formats will vary among archival institutions given their capabilities, there is documented acceptance among the field that chosen file formats should be "open, standard, non-proprietary, and well-established" to enable long-term archival use.<ref name=":03">{{Cite web|url=https://siarchives.si.edu/what-we-do/digital-curation/recommended-preservation-formats-electronic-records|title=Recommended Preservation Formats for Electronic Records|last=bradyh|date=2017-04-26|website=Smithsonian Institution Archives|access-date=2019-04-29}}</ref> Factors that should enter consideration when selecting sustainable file formats include disclosure, adoption, transparency, self-documentation, external dependencies, impact of patents, and technical protection mechanisms.<ref>{{cite web|url=http://www.digitalpreservation.gov/formats/sustain/sustain.shtml |title=Sustainability Factors |work=digitalpreservation.gov |url-status=live |archive-url=https://web.archive.org/web/20141013230220/http://www.digitalpreservation.gov/formats/sustain/sustain.shtml |archive-date=2014-10-13 }}</ref> Other considerations for selecting sustainable file formats include "format longevity and maturity, adaptation in relevant professional communities, incorporated information standards, and long-term accessibility of any required viewing software".<ref name=":03"/> For example, the [[Smithsonian Institution Archives]] considers uncompressed [[TIFF]]s to be "a good preservation format for born-digital and digitized still images because of its maturity, wide adaptation in various communities, and thorough documentation".<ref name=":03"/>

Formats proprietary to one software vendor are more likely to be affected by format obsolescence. Well-used standards such as [[Unicode]] and [[JPEG]] are more likely to be readable in future.

====Significant properties====
Significant properties refer to the "essential attributes of a digital object which affect its appearance, behavior, quality and usability" and which "must be preserved over time for the digital object to remain accessible and meaningful."<ref>{{cite web |url=http://www.jisc.ac.uk/whatwedo/programmes/preservation/2008sigprops.aspx |title=The Significant Properties of Digital Objects |website=Jisc |date=April 7, 2008 |access-date=March 28, 2022 |archive-url=https://web.archive.org/web/20141014154001/http://www.jisc.ac.uk/whatwedo/programmes/preservation/2008sigprops.aspx |archive-date=October 14, 2014}}</ref>

"Proper understanding of the significant properties of digital objects is critical to establish best practice approaches to digital preservation. It assists appraisal and selection, processes in which choices are made about which significant properties of digital objects are worth preserving; it helps the development of preservation metadata, the assessment of different preservation strategies and informs future work on developing common standards across the preservation community."<ref>{{cite journal |url=http://www.ils.unc.edu/callee/sigprops_dlm2002.pdf |title=Significant Properties of Digital Objects: Definitions, Applications, Implications |last1=Hedstrom |first1=Margaret |first2=Christopher A. |last2=Lee |journal=Proceedings of the DLM-Forum 2002 Parallel Session 3 |date=2002 |pages=218–233 |publisher=University of North Carolina: School of Information and Library Science |archive-url=https://web.archive.org/web/20070703013435/http://www.ils.unc.edu/callee/sigprops_dlm2002.pdf |archive-date=July 3, 2007}}.</ref>

===Authenticity===
Whether analog or digital, archives strive to maintain records as trustworthy representations of what was originally received. Authenticity has been defined as ". . . the trustworthiness of a record as a record; i.e., the quality of a record that is what it purports to be and that is free from tampering or corruption".<ref>{{cite web|title=InterPARES 2 Terminology Database - authenticity |work=web site |year=2007 |url=http://www.interpares.org/ip2/ip2_terminology_db.cfm |access-date=8 October 2014 |url-status=live |archive-url=https://web.archive.org/web/20141007022207/http://www.interpares.org/ip2/ip2_terminology_db.cfm |archive-date=7 October 2014 }}</ref> Authenticity should not be confused with accuracy;<ref>{{cite web|title=Society of American Archivists Glossary - accuracy |work=web site |year=2014 |url=http://www2.archivists.org/glossary/terms/a/accuracy |access-date=8 October 2014 |url-status=live |archive-url=https://web.archive.org/web/20141012221951/http://www2.archivists.org/glossary/terms/a/accuracy |archive-date=12 October 2014 }}</ref> an inaccurate record may be acquired by an archives and have its authenticity preserved. The content and meaning of that inaccurate record will remain unchanged.

A combination of policies, security procedures, and documentation can be used to ensure and  provide evidence that the meaning of the records has not been altered while in the archives' custody.

===Access===
Digital preservation efforts are largely to enable decision-making in the future. Should an [[archive]] or library choose a particular strategy to enact, the content and associated metadata must persist to allow for actions to be taken or not taken at the discretion of the controlling party.

===Preservation metadata===
[[Preservation metadata]] is a key enabler for digital preservation, and includes technical information for digital objects, information about a digital object's components and its computing environment, as well as information that documents the preservation process and underlying rights basis. It allows organizations or individuals to understand the [[chain of custody]]. [[Preservation Metadata: Implementation Strategies|Preservation Metadata: Implementation Strategies (PREMIS)]], is the de facto standard that defines the implementable, core preservation metadata needed by most repositories and institutions. It includes guidelines and recommendations for its usage, and has developed shared community vocabularies.<ref>PREMIS Data Dictionary (full document), Version 3.0 https://www.loc.gov/standards/premis/v3/premis-3-0-final.pdf</ref><ref>Dappert, Angela; Guenther, Rebecca Squire; Peyrard, Sébastien (2016). Digital Preservation Metadata for Practitioners. doi:10.1007/978-3-319-43763-7. {{ISBN|978-3-319-43761-3}}.</ref>