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space A Framework of Guidance for Building Good Digital Collections

Printer Friendly Version

November 6, 2001 

The following report was prepared by members of the Digital 

Library Forum, a group convened by the Institute of Museum and 

Library Services (IMLS) to discuss issues relating to the 

implementation and management of networked digital libraries. 

Members quickly identified collection quality as a critical aspect 

of digital library management and interoperability, and this 

understanding forms the foundation of the report. 

The Framework is intended as a resource for grant applicants, 

IMLS and other federal funding agencies, rather than as a set of 

requirements.

Forum members who contributed to the report include: Liz 

Bishoff, Colorado Digitization Alliance; Priscilla Caplan (chair), 

Florida Center for Library Automation; Tim Cole, University of 

Illinois Urbana-Champaign; Anne Craig, Illinois State Library; 

Daniel Greenstein, Digital Library Federation; Doug Holland, 

Missouri Botanical Garden; Ellen Kabat-Lensch, Eastern Iowa 

Community College; Tom Moritz, American Museum of Natural 

History; and John Saylor, Cornell University.

INTRODUCTION

This Framework is intended for two audiences: first, for people 

who are working in the context of projects and want to develop 

good digital collections; and second, for funding organizations 

and agencies that want to encourage the creation of good digital 

collections. 

The use of the word good in this context requires some 

explanation. In the early days of digitization for the Web, projects 

could be justified as vehicles for the development of methods and 

technologies, as experiments in technical or organizational 

innovation, or simply as learning experiences. A collection could 

be good if it provided proof of concept, even if it disappeared at 

the end of the project period. As the environment matured, the 

focus of collection building shifted towards the more utilitarian 

goal of making relevant content available digitally to some 

community of users. The bar of goodness was accordingly raised 

white 

space
to include levels of usability, accessibility and fitness for use 

appropriate to the anticipated user group. We have now entered a 

third stage, where even serving information effectively to a known 

constituency is not sufficient. In today's digital environment, the 

context of content is a vast international network of digital 

materials and services. Objects, metadata and collections should 

be viewed not only within the context of the projects that created 

them but as building blocks that others can reuse, repackage, and 

build services upon. Indicators of goodness correspondingly must 

now also emphasize factors contributing to interoperability, 

reusability, persistence, verification and documentation. At the 

same time attention must be focused on mechanisms for 

respecting copyright and intellectual property law. 

This document is not a guideline itself but rather a framework for 

identifying, organizing, and applying existing knowledge and 

resources that can be used as an aid in the development of local 

guidelines and procedures. It is built around indicators of 

goodness for four types of entities: 

● Collections, 

● Objects, 

● Metadata, and 

● Projects. 

Note that services have been deliberately excluded as out of 

scope, but it is expected that if quality collections, objects and 

metadata are created, it will be possible for any number of higher 

level services to make use of these entities. 

In each category, general principles relating to quality are defined 

and discussed, and supporting resources are identified. These 

resources may be standards, guidelines, best practices, 

explanations, discussions, clearinghouses, case studies or 

examples. Every effort has been made to be selective and to 

include only materials that are useful, current and widely accepted 

as authoritative. However, the value of some resources will in 

time be depreciated and other resources created or discovered, so 

it is fully expected this list will change over time. It is hoped that 

this framework will be flexible enough to accommodate new 

principles, considerations and resources, and to absorb the 

contributions of others. 

There are no absolute rules for creating good collections, objects 

or metadata. Every project is unique and each has its own goals. 

There are almost as many ways of categorizing collections as 

there are collections. Projects dealing with legacy collections or 

with born-digital materials, for example, have different constraints 

than projects just embarking on new digitization. Museums, 

libraries, and school boards have different constituencies, 

priorities, institutional cultures, funding mechanisms and 

governance structures. The key to a successful project is not to 
follow any particular path, but to think strategically and make 

wise choices. To use the Framework successfully, project planners 

should take into consideration their organizational goals, their 

audience, and the content available to them, and they should select 

the set of principles and resources that best meet their project's 

needs. Following sound guidelines will help guarantee that 

collections will not only serve known local needs but will be 

reusable in new and innovative contexts. 

A number of excellent resources take a holistic view of 

digitization projects. It is recommended that projects consult these 

or other general guides to digitization projects. 

● Northeast Document Conservation Center. Handbook for 

Digital Projects: A Management Tool for Preservation & 

Access. http://www.nedcc.org/digital/dighome.htm

● Anne R. Kenney and Oya Y. Rieger. Moving Theory into 

Practice: Digital Imaging for Libraries and Archives. 

Research Libraries Group, 2000. An online tutorial at http://

www.library.cornell.edu/preservation/tutorial/ 

serves as an introduction to topics covered more 

extensively in the printed volume. 

COLLECTIONS 

A digital collection is more than just an assemblage of objects. In 

the context of this Framework, a collection can be defined as a 

selected and organized set of digital materials (objects) along with 

the metadata that describes them and at least one interface that 

gives access to them. As such, the whole is greater than the sum 

of the parts. Digital collections are generally created by 

organizations or groups of cooperating organizations, often as part 

of a project. 

Principles applying to good collections 

Collections principle 1: A good digital collection is created 

according to an explicit collection development policy that has 

been agreed upon and documented before digitization begins.

Of all factors, collection development is most closely tied to an 

organization's own goals and constituencies. Collection builders 

should be able to summarize the mission of their organization and 

articulate how a proposed collection furthers or supports that 

mission. Project managers should be able to identify the target 

audience(s) for the collection (both in the short term and in the 

future) and how the selected materials relate to their audience. 

There is an often unexamined assumption that digitization will 

dramatically increase the use or value of materials. If the materials 

exist in non-digital form, how heavily are they used? What factors 

specifically will influence their use or value when digitized? 
Consider how the digital collection will fit in with the 

organization's overall collection policy, as digital collections 

should not stand in isolation from the original materials or from 

the collection as a whole. 

The following documents are guidelines for selecting materials for 

digitization. The list does not include electronic collection 

development policies, which are documents drafted to guide 

libraries in their selection of commercially available resources. 

● Joint RLG and NPO Preservation Conference, Guidelines 

for Digital Imaging: Guidance for selecting materials for 

digitisation. http://www.rlg.org/preserv/joint/ayris.html

● Moving Theory into Practice. Digital Imaging Tutorial: 

Selection. http://www.library.cornell.edu/preservation 

/tutorial/selection/selection-01.html

● Dan Hazen, Jeffrey Horrell, and Jan Merrill-Oldham. 

Selecting research collections for digitization (CLIR, 

August 1998) http://www.clir.org/pubs/abstract/pub74.

html

● Towards a Learning Nation: The Digital Contribution. 

Recommendations proposed by the Federal Task Force on 

Digitization. Final Report. (December 31, 1997). Part B 

Issue 2: Selecting materials for digitization. 

http://www.nlc-bnc.ca/8/3/r3-407-e.html

A report of the DLESE Collections Committee, "How to Identify 

the "Best" Resources for the Reviewed Collection of the Digital 

Library for Earth System Education" describes a distributed 

selection process that could be applied to other learning resources. 

http://www.ldeo.columbia.edu/DLESE/collections/CGms.html

The Digital Library Federation maintains a database of digital 

library documents that include collection development policies of 

a number of DLF members. Some of these policies concern all 

electronic acquisitions while others focus on retrospective 

digitization. 

http://www.hti.umich.edu/cgi/b/bib/bib-idx?c=dlf

Some examples of local collection development policies include: 

● Columbia University Libraries Selection Criteria for 

Digital Imaging. 

http://www.columbia.edu/cu/libraries/digital/criteria.html

● University of California Selection Criteria for Digitization. 

http://www.library.ucsb.edu/ucpag/digselec.html

● North Carolina ECHO (Exploring Cultural Heritage 

Online) Guidelines, Section 2: Planning & Selection. http://

www.ncecho.org/Guide/selection.htm The ECHO project 

includes materials from libraries, archives and museums. 
There are also a number of guidelines for selecting materials for 

digitization specifically for preservation purposes: 

● Selection Criteria for Preservation Digital Reformatting. 

Library of Congress Preservation Reformatting Division. 

http://lcweb.loc.gov/preserv/prd/presdig/ 

presselection.html

● Joint RLG and NPO Preservation Conference, Guidelines 

for Digital Imaging: Selection Guidelines for Preservation. 

http://www.rlg.org/preserv/joint/gertz.html

Collection builders should be aware that special constraints may 

exist in relation to politically and culturally sensitive materials. 

Even items that are unexceptional in the context of a repository 

can be disturbing when taken out of context. Selection guidelines 

with particular attention to sensitivity are included in the 

Northeast Documentation and Conservation Center's Handbook 

for Digital Projects, chapter IV: Selection of Materials for 

Scanning by Diane Vogt-O'Connor. http://www.nedcc.org/digital/

IV.htm. 

Collections principle 2: Collections should be described so that a 

user can discover important characteristics of the collection, 

including scope, format, restrictions on access, ownership, and 

any information significant for determining the collection's 

authenticity, integrity and interpretation.

Collection description is a form of metadata (see also 

METADATA). Collection description serves two purposes: it 

helps people discover the existence of a collection (whether they 

are end-users seeking materials relevant to their information 

needs, or other collection-builders looking for similar or 

complementary materials), and it helps users of the collection 

understand what they are looking at. 

To serve the first purpose, when possible, collections should be 

described in collection-level cataloging records contributed to a 

national union catalog such as the OCLC or RLIN databases. 

Websites and individual digital objects can be cataloged through 

OCLC's CORC. There are also a number of directories where 

collections can be registered. A few of these are listed below; for 

a more complete list see the inventory of directories of Webaccessible collections in the December 2000 issue of RLG 

DigiNews. http://www.rlg.org/preserv/diginews/diginews4-6.

html#faq

● The UNESCO/IFLA Directory of Digitized Collections 

lists major cultural heritage collections and programs 

worldwide. http://thoth.bl.uk

● The University of Arizona maintains a Clearinghouse of 
Image Databases. http://www.library.arizona.edu/images 

/clearinghouse/clearinghouse.html

● The Association of Research Libraries maintains a 

database of digital initiatives that includes technical as well 

as collections information. http://www.arl.org/did/index.

html

● The Smithsonian Institution maintains a list of Library and 

Archival Exhibitions on the Web. http://www.sil.si.edu/

SILPublications/Online-Exhibitions/online-exhibitionsframes.htm

After a user has discovered a relevant collection, collection 

description should help him understand the nature and scope of 

the collection and any restrictions that apply to the use of 

materials within it. Incorporating a narrative description of the 

collection on its Web site in human readable prose is good 

practice. There should be a description of the materials 

comprising the collection, including how and why they were 

selected. The organization(s) responsible for building and 

maintaining the collection should be clearly identified, as 

organizational provenance is important in helping the user to 

evaluate the authenticity and authority of the collection. Terms 

and conditions of use, restrictions on access, special software 

required for general use, the copyright status(es) of collection 

materials, and contact points for questions and comments should 

be noted. Many project planners find a description of the 

methodologies, software applications, record formats, and 

metadata schemes used in building other collections helpful. 

Good examples of collection-level terms and conditions of use are 

provided by JSTOR and Ad*Access Project. For examples of 

Web sites with extensive technical and project documentation, see 

Ad*Access and Historic Pittsburgh. 

There do not appear to be many guidelines specifically for 

describing digital collections generally, as opposed to archival 

collections. The Collection Description project of the UK's 

Research Support Libraries Programme has a Web site of 

materials related to collection description including an RDF-based 

collection description schema intended to be both human and 

machine-readable. The set of data elements included in this 

schema can be used as a checklist of information a project might 

want to provide about its collection. 

Archival collections are generally described by curators according 

to established principles of archival description. (See also 

METADATA.) 

● The General International Standard Archival Description. 

(ISAD(G)) is a set of general rules for archival description 
developed by the International Council on Archives. 

● The Encoded Archival Description (EAD) is a scheme for 

representing archival finding aids in machineunderstandable form using SGML as a markup language. 

http://www.loc.gov/ead/

● A standard developed for describing government agencies, 

collections and services. Global Information Locator 

Service (GILS). http://www.gils.net/

Collections principle 3: A collection should be sustainable over 

time. In particular, digital collections built with special funding 

should have a plan for their continued usability beyond the funded 

period. 

Sustainability at the collection level is related to, but not identical 

with, persistence at the object level (see OBJECTS). Certainly the 

collection-level archiving strategy should be tied to the 

preservation strategy at the object level. Managers of collections 

containing materials of long-term importance should take steps to 

ensure not only that the objects within them will be preserved in 

usable form over time, but that collection-level access to the 

materials is maintained. 

This implies, first and foremost, that some organizational 

responsibility for the ongoing maintenance of the collection is 

established. Collection maintenance may take different sets of 

skills and different commitments of resources than the original 

collection building. Aspects of ongoing maintenance include such 

functions as maintaining the currency of locations, ensuring that 

search systems and other access applications remain usable, 

logging and accumulating statistics, and providing some level of 

end-user support. They also include the system administration 

functions of upgrading server hardware and operating system 

software as required over time, maintaining server security, and 

ensuring that restoration of applications and data from backups is 

always possible. 

Two works that focus on creating portals to third-party resources 

(rather than creating new digital content) focus on sustainability 

are: 

● The DESIRE Information Gateways Handbook, which 

contains generally useful information on link checking and 

related maintenance activities in a section on collection 

management. http://www.desire.org/handbook/

● Pitschmann, Louis A. Building Sustainable Collections of 

Free Third-Party Web Resources. (Washington, DC: 

Digital Library Federation, Council on Library and 

Information Resources, June 2001) http://www.clir.org/

pubs/abstract/pub98abst.html
Collections principle 4: A good collection is broadly available 

and avoids unnecessary impediments to use. Collections should be 

accessible to persons with disabilities, and usable effectively in 

conjunction with adaptive technologies.

At this time, the World Wide Web is the vehicle for broad 

availability. Collections should be accessible through the Web and 

should use technologies that are ubiquitous among the target user 

community. There is always a tradeoff between functionality and 

general usability; the timing of the adoption of new features such 

as frames and style sheets should be considered in light of how 

many potential users will be capable of using the technology and 

how many will find it a barrier. Bandwidth requirements are also a 

consideration, as some file formats or interfaces may not be 

usable by individuals on low-bandwidth connections. The 

minimum browser version and bandwidth requirements for use 

should be documented as part of the collection description. 

The webreview site offers reference guides to style sheets and 

Web browsers. Their browser compatibility chart compares 

features supported by all versions of the major browsers. http://

www.webreview.com/browsers/browsers.shtml

The report Performance Measures for Federal Agency Websites

by Chuck McClure et. al. addresses Web site design in terms of 

efficiency, effectiveness, service quality, impact, usefulness and 

extensiveness. http://fedbbs.access.gpo.gov/library/download 

/MEASURES/measures.doc

Accessibility is not only good policy, it is also the law as 

embodied in the Americans with Disabilities Act of 1990. The 

International Center for Disability Resources on the Internet 

publishes An Overview of Law & Policy for IT Accessibility. http://

www.icdri.org/SL508overview.html

The current de facto accessibility standard is the World Wide Web 

Consortium (W3C) Web Content Accessibility Guidelines 1.0. 

http://www.w3.org/TR/WAI-WEBCONTENT/

An example of how these guidelines can be applied in an 

institutional context is given by the Yale University Library. Their 

document Services for Persons with Disabilities has a section on 

Web Accessibility Guidelines which also lists other accessibility 

resources http://www.library.yale.edu/Administration/SQIC/ 

spd2.html#s3.. 

The Bobby application will check a web page or web site for 

barriers to persons with disabilities. Bobby is a free service 

offered by CAST, the Center for Applied Special Technology. 

http://www.cast.org/bobby/
There are several clearinghouses that focus on Web accessibility: 

● CPB/WGBH National Center for Accessible Media has a 

number of accessibility initiatives including projects 

focused on educational materials. http://ncam.wgbh.org/

education/index.html

● University of Wisconsin. Trace Research and Development 

Center. Designing More Usable Websites. A clearinghouse 

of useful tools, initiatives, documentation and websites. 

http://trace.wisc.edu/world/web/

Collections principle 5: A good collection respects intellectual 

property rights. Collection managers should maintain a consistent 

record of rightsholders and permissions granted for all applicable 

materials. 

Intellectual property law must be considered from several points 

of view in relation to any collection: what rights the owners of the 

original source materials retain in their materials; what rights or 

permissions the collection developers have to digitize content and 

make it available; what rights collection owners have in their 

digital content; and what rights or permissions the users of the 

digital collection have to make subsequent use of the materials. 

Viewed from any side, rights issues are rarely clear cut, and the 

rights policy related to any collection is more often a matter of 

risk management than one of absolute right and wrong. 

There are a number of clearinghouses on law and policy related to 

copyright and intellectual property. The International Federation 

of Library Associations maintains a site with international scope 

at http://www.ifla.org/II/cpyright.htm. The Library of Congress 

Copyright Office maintains a site that combines both general and 

procedural information. http://www.loc.gov/copyright/

An excellent introduction to virtually all copyright-related issues 

is the Copyright Crash Course by Georgia Harper at the 

University of Texas at Austin (http://www.utsystem.edu 

/ogc/intellectualproperty/cprtindx.htm). There is a particularly 

useful section on the logistics of obtaining permission http://www.

utsystem.edu/ogc/intellectualproperty 

/permissn.htm which takes the perspective of risk vs. benefit. 

The National Initiative for a Networked Cultural Heritage 

(NINCH) has held a series of "Town Meetings" that combine 

experts' presentations with open discussion on topics such as 

copyright, fair use, and distance education. Reports of past 

meetings and the schedule of future meetings are available at 

http://www-ninch.cni.org/copyright/townmeetings01/2001.html
A multimedia publishing company has published primers for 

multimedia developers. "Intellectual Property Law Primer for 

MultiMedia Developers" http://www.timestream.com/stuff/

neatstuff/mmlaw.html "Licensing Still Images: Some Basic 

Information for Multimedia Developers." http://www.timestream.

com/stuff/neatstuff/license.html

Collections principle 6: A good collection provides some 

measurement of use. Counts should be aggregated by period and 

maintained over time so that comparison can be made.

Measures can include use counts ("x files retrieved"), user 

analysis ("this site was visited by x users from y different 

domains"), or "linked-to" counts ("this site is linked to by n other 

sites"). Since measures should be maintained over time, they take 

some resources to support, and the measures chosen should be 

designed to serve some purpose of the sponsoring project or 

organization. One common use is to attempt to justify resources 

devoted to a collection by volume of use, either generally or 

within a certain user population. Another use is to enlighten 

collection development policy. Metrics are also a tool in the 

evaluation of projects and collections (see PROJECTS). 

There are no formal standards for measuring use of electronic 

content, whether remotely available commercial resources or 

locally provided collections. The most widely used guidelines 

were developed by the International Coalition of Library 

Consortia (ICOLC) as a guide to what measures should be 

reported by vendors. Guidelines for statistical measures of usage 

of web-based indexed, abstracted and full text resources

(November 1998). http://www.library.yale.edu/consortia/webstats.

html

The Association of Research Libraries has an initiative to develop 

measures for electronic resources (e-metrics) that includes both 

commercial resources and local digital collections. http://www.arl.

org/stats/newmeas/emetrics/index.html

The National Information Standards Organization has an initiative 

to revise Z39.7, a standard for library statistics, to include better 

measures for electronic resources. Watch the NISO Web site 

(http://www.niso.org) for progress information about this effort. 

The Report on the NISO Forum on Performance Measures and 

Statistics for Libraries contains a useful "webography". http://

www.niso.org/stats-rpt.html

Collections principle 7: A good collection fits into the larger 

context of significant related national and international digital 

library initiatives. For example, collections of content useful for 

education in science, math and/or engineering should be usable in 
the NSDL.

One primary means of fitting into a larger context is paying 

attention to interoperability issues, particularly the ability to 

contribute metadata to more inclusive search engines. However, 

other means are also important. These include being aware of and 

in contact with related efforts, following widely accepted 

benchmarks for quality of content and of metadata, and providing 

adequate collection description for users to place one collection in 

the context of others. 

Some examples of widely known national and international 

initiatives include: 

● The Open Archives Initiative. http://www.openarchives.

org/

● The National SMETE (Science Mathematics Engineering 

and Technology Education) Digital Library. Pathways to 

progress: vision and plans for developing the NSDL. http://

www.smete.org/nsdl/ 

workgroups/coordcomm/Whitepaper.doc

● The Research Libraries Group's Cultural Materials 

Initiative. http://www.rlg.org/culturalres/

● The Art Museum Image Consortium. http://www.amico.

org/

Topical collections may fit into broader clearinghouses or 

cooperative portals. Project planners should search for 

clearinghouses in their subject area; there is an increasing number 

of clearinghouses, particularly in areas related to scientific or 

environmental information. For example: 

● The Geospatial Data Clearinghouse is a collection of over 

250 spatial data servers, that have digital geographic data 

primarily for use in Geographic Information Systems 

(GIS), image processing systems, and other modeling 

software. http://fgdclearhs.er.usgs.gov/

● The Global Biodiversity Information Facility aims for 

"compilation, linking, standardisation, digitisation and 

global dissemination of the world's biodiversity data". 

http://www.gbif.org/index.html

Cooperative portals are gateways to existing Web sites and other 

resources maintained collaboratively by a group of institutions, 

each taking responsibility for selecting quality resources within 

some subtopic of a larger subject area. Some examples include: 

● Healthweb, a cooperative project of about 20 health 

sciences libraries for health-related resources. http://

healthweb.org/
● Agnic, a portal to agricultural information being developed 

by the National Library of Agriculture, land grant 

universities and other partners. http://www.agnic.org/

OBJECTS

This Framework is concerned with two kinds of digital objects: 

those produced as surrogates for information objects that exist in 

some analog format (e.g. as books, manuscripts, museum artifacts, 

audio or video tapes, etc.), and those that are born digital, that is, 

that are produced originally in machine-readable form (scientific 

databases, sensory data, digital photographs, etc.). A good object 

that is created as a surrogate will be considered by a community to 

be a faithful facsimile of the artifact. 

For the context of this Framework, collections (see 

COLLECTIONS) consist of objects. In this sense, objects are 

equivalent conceptually to the items that may be found amongst 

library holdings (books), museum collections (artifacts), and 

archival fonds (papers). Obviously no hard and fast line can be 

drawn between objects and collections. Our definition of object 

extends to compound objects such as the digitally reformatted 

book or serial publication, but not as far as a collection (which in 

this case would include, for example, two or more digitally 

reformatted book or serial publications). 

When speaking of digital objects, it is often useful to distinguish 

between master or preservation copies and access or use copies. 

As their names imply, masters are typically the highest quality 

versions that the production technique allows while use or access 

copies are derivatives that are created for specific uses, 

distribution scenarios, or users. Thus, a master copy a of a 

digitally reformatted 35mm slide might be an uncompressed, 18 

megabyte, TIFF file, captured in 24-bit color, at a resolution of 

600 dots per inch (dpi). The access or derivative copy of this 

might be a 150 KB, JPEG image derived from the TIFF file, 

which will allow a reasonable download time for the average Webbased user. Where both master and use copies are created (in 

many instances, the master copy also serves as the use copy) the 

principals outlined below apply to the master copy, though some 

apply equally well to the use copy. 

Among the advantages in reaching agreement about what 

constitutes good objects are the following: 

● By agreeing to minimum level benchmarks for good 

objects, organizations that produce such objects can reduce 

the risk involved in producing and maintaining them while 

inspiring confidence in and encouraging their use. 

● Because good objects will be considered capable of 

meeting known current and likely future needs, 
organizations can invest in their creation secure in the 

knowledge that they will not be forced to re-create the 

objects at some future date even as production techniques 

improve. 

● Users of good objects will develop confidence in the 

objects because they will have a minimum level of wellknown and consistent properties, and will support a variety 

of known uses. 

● By building consensus around the characteristics of good 

objects organizations that produce and support their use 

will be able more effectively to: 

write contracts with vendors who create such 

objects and to compare vendors' prices 

❍ commit to making good objects accessible over the 

longer term - good objects will be invested with an 

intrinsic value that makes them worth maintaining 

❍ level up their data creation efforts to a point where 

they produce objects of known quality capable of 

supporting a number of known uses 

❍ instill confidence in users who will know that good 

objects support their needs 

❍ define and narrow preservation options as may be 

required to migrate or emulate good objects 

Principles applying to good objects 

Objects principle 1. A good digital object will be produced in a 

way that ensures it supports collection priorities. 

How a digital object is produced and described will determine 

whether, how, by whom and at what cost to whom it can be 

accessed and used over the longer term. Accordingly, decisions 

about how objects are produced and described should reflect and 

follow from those made about why they are being produced and 

for whom or what purpose. For that reason, the guidelines for 

selection listed in COLLECTIONS are equally relevant to the 

creation of good objects. 

Some examples of how decisions about production and 

description should follow naturally from strategic collection 

development decisions are available in Neil Beagrie and Daniel 

Greenstein, "A Strategic Policy for Creating and Preserving 

Digital Collections (1998). http://www.ahds.ac.uk/strategic.pdf 

Objects principle 2. A good object is persistent. That is, it will be 

the intention of some known individual or institution that the good 

object will persist; that it will remain accessible over time despite 

changing technologies.

Digital information is notoriously volatile. Imagine the difficulties 

involved ten (let alone 50 or 100!) years from now in accessing a 
digital object that is created today. Even if the physical medium (e.

g., CD, hard drive) that carries the object survives uncorrupted, it 

is unlikely that a computer will exist that is capable of reading the 

medium. How many computers are today are capable of handing 

5.25-inch floppy disks? And even if such computers are found to 

exist, it isn't clear they will have the operating systems or software 

capable of rendering the machine-readable information into 

something that can be made sensible to a user with then-current 

software. 

Two strategies are available to ensure that objects persist. The 

first is migration. It involves transforming objects so they can 

move between technical regimes as those regimes change. 

Migration occurs at all levels, as objects are moved: 

● across media as media evolve (e.g. from diskette to CD, 

and from CD to optical disk or DAT tape); 

● across software products as the products become outmoded 

(e.g. from one version of a word-processing or database 

package to another); and, 

● across formats as formats evolve (e.g. from SGML to 

XML, as is the case today with so many encoded ASCII 

texts). 

The second strategy involves emulation. This assumes that in 

some cases, it is better (involves less expense and/or less 

information loss) to emulate on contemporary systems the 

computer environment in which digital objects were originally 

created and used. Emulation strategies may be particularly 

appropriate for complex multimedia objects such as interactive 

learning modules. 

Although no single production decision about format, 

compression, etc. will guarantee that an object will persist, some 

decisions are safer than others. Some formats, at least, will be 

easier to maintain at lower cost across changing technical regimes. 

A good object, then, will either have a known preservation 

strategy (e.g. as with SGML-encoded ASCII texts where 

migration through changing regimes is both known and deemed 

viable and cost effective) or a good chance of evolving such a 

strategy (e.g. where widespread commercial investment in the 

format- PDF - makes development of an effective preservation 

strategy highly likely). 

A large and growing literature on digital preservation exists. Some 

particularly salient references include: 

● PADI (Preservation Access to Digital Information), a 

comprehensive, well-maintained clearinghouse to all types 

of information resources related to digital preservation. 

http://www.nla.gov.au/padi/
● Reference Model for an Open Archival Information 

System. This reference model, currently in an ISO 

standards track, provides a high-level conceptual 

framework for thinking about persistence and preservation 

of digital objects. http://ssdoo.gsfc.nasa.gov/nost/isoas/

overview.html

● Gregory W. Lawrence, William R. Kehoe, Oya Y. Rieger, 

William H. Walters, and Anne R. Kenney, Risk 

Management of Digital Information: A File Format 

Investigation (CLIR 2000). This report is based on an 

investigation conducted by Cornell University Library to 

assess the risks to digital file formats during migration. 

http://www.clir.org/pubs/abstract/pub93abst.html

● Jeff Rothenberg, Avoiding Technological Quicksand: 

Finding a Viable Technical Foundation for Digital 

Preservation (CLIR 1999). Elaborates a proposal for 

emulating obsolete software/hardware systems on future, 

unknown systems, as a means of preserving digital 

information far into the future. http://www.clir.org/pubs/

abstract/pub77.html

● Conservation On-Line (COOL) Preservation of Audio 

Materials. A clearinghouse of resources related to 

preserving both digital and analog audio. http://sul-server-2.

stanford.edu/bytopic/audio/

Objects principle 3. A good object is digitized in a format that 

supports intended current and likely future use or that support the 

development of access copies that support those uses. 

Consequently, a good object is exchangeable across platforms, 

broadly accessible, and will either be digitized according to a 

recognized standard or best practice or deviate from standards 

and practices only for well documented reasons.

In almost every case, there is a direct correlation between the 

production quality of a digitized object and the readiness and 

flexibility with which that object may be migrated across 

platforms. As a result, the digitization of objects at the highest 

affordable quality can pay off in the long run as the objects are 

rendered more useful and more flexibly accessible over the longer 

term. 

Having said that, not all objects require such investment. A 

spreadsheet that is used to calculate 2001 tax liabilities, or a 

digital image showing Michael, age 3.5 on his new bike may have 

substantial local and immediate value but also very limited longterm worth. The spreadsheet might be printed out and included in 

a personal paper archive until destroyed whenever the statute of 

limitations expires. The picture of young Michael may be created 

from a 35mm slide that is considered to be the long-term master. 

In both cases, there is very good reason to invest as little as 

possible in the creation of persistent objects. The point is that 
nearly every digitization project needs to determine the value of 

the digitized objects themselves and to make appropriate decisions 

about persistence and interoperability. 

Formats are presented Table 1 below. They are organized 

according to a typology that recognizes data types, and within 

data types, applications to which objects of that type may be put. 

The approach (derived from one that has become common in 

Europe) is extensible with respect both to the number of data 

types and applications that it recognizes. 

TABLE 1. A TYPOLOGY OF FORMATS 

DATA TYPE APPLICATIONS FORMATS GUIDELINES 

and 

REFERENCES

Alphanumeric 

data

Flat files; 

hierarchical or 

relational datasets.

Commadelimited 

ASCII, or 

portable 

format files 

recognized as 

de facto 

standards (e.

g. SAS and 

SPSS) with 

enough 

metadata to 

distinguish 

tables, rows, 

columns, etc.

For social science 

and historical 

datasets, see 

Guide to Social 

Science Data 

Preparation and 

Archiving 

(ICPSR 2000) 

http://www.icpsr. 

umich.edu 

/ACCESS/ 

dpm.html, and 

Digitizing 

history, a guide to 

creating 

electronic 

resources from 

historic 

documents (HDS, 

1999) http://hds.

essex. 

ac.uk/g2gp 

/digitising_ 

history 

/index.aspm.

Encoded texts for 

networked

SGML, 

XML; use 

documented 

DTD's

presentation and 

exchange of textbased information

or schema
Encoded texts for 

literary and 

linguistic content 

analysis

SGML, XML Text Encoding 

Initiative (TEI) 

http://www. 

tei-c.org. 

Creating and 

documenting 

electronic texts 

(OTA, 1999) 

http://hds.essex. 

ac.uk/g2gp/ 

digitizing_history 

/index.asp and 

TEI text encoding 

in Libraries: 

Guidelines for 

Best Practice 

(DLF, 1999) 

http://www.diglib. 

org/standards 

/tei.htm

Image data 

(raster 

graphics)

bitonal, 

grayscale and 

color images 

of pictures, 

documents, 

maps, 

photographs

Book or serial 

publication 

prepared as 

preservation 

digital master or 

access surrogate 

for source

Archival 

masters 

likely to be 

TIFF files at 

color depth 

and 

pixelation 

appropriate 

for 

application. 

Derivative 

data likely to 

vary 

depending on 

use

Anne R. Kenney, 

Oya Y. Rieger, et 

al Report of the 

Digital 

Preservation 

Policy Working 

Group on 

Establishing a 

Central 

Depository for 

Preserving 

Digital Image 

Collections 

(March 2001) at 

http://www.library 

.cornell.edu/ 

preservation 

/IMLS/image_ 

deposit 

_guidelines.pdf 

Library of 

Congress, The 

Preservation 

Digital 

Reformatting 

Program: Image 

Specifications 

(September 2001).
The most recent 

consensus is 

available in Draft 

benchmark for 

digital 

reproductions of 

book and serial 

publications 

(DLF, 2001), at 

http://www.diglib. 

org/standards/ 

draftbmark.htm

An example of 

one institution's 

local benchmarks:

California Digital 

Library. Digital 

Object Format 

Standards. http://

www.cdlib. 

org/about/ 

publications/ 

CDLImageStd1001.pdf

Scalable 

image data 

(vector 

graphics)

presentations, 

creative 

graphics, 

computeraided designs, 

clip art, line 

drawings, 3-D 

models, maps

maps, herbarium 

specimens

MrSid from 

LizardTech 

becoming a 

de facto 

standard 

although 

proprietary

Audio music audio Archival 

masters 

likely to be 

IFF or AIFF. 

Delivery 

formats may 

be RealAudio.

A brief technical 

introduction to 

Digital Audio by 

the National 

Library of 

Canada http://

www.nlc-bnc.

ca/9/1/p1-148-e.

html. Harvard 

University 

Library Digital 

Initiative Audio 

Reformatting 

http://hul.harvard 

.edu/ldi/html/ 

reformatting_ 

audio.html. 
Currently the site 

has links to 

industry 

standards and will 

include project 

guidelines in the 

future.Sound 

Practice: A 

Report on the 

Best Practices for 

Digital Sound 

Meeting, 16 

January 2001 at 

the Library of 

Congress http://

www.rlg.org/ 

preserv/diginews 

/diginews5-1.html 

#feature3

spoken word (e.g. 

oral histories)

See music audio 

above.National 

Gallery of the 

Spoken Word 

http://www.

matrix. 

msu.edu/ngsw 

/cfm/tech_ 

issues.cfm. Old 

Dominion 

University online Digital 

Training 

Workshop 2000 

http://www.lib.

odu. 

edu/services/ 

dcenter/dtw2000 

/index.html

Video

In process

Multimedia GIS GIS often 

combines 

data in 

multiple 

formats: 

GPS, 

alphanumeric 

data (e.g. as 

required to 

record coordinate 

data), vector 

and raster 

GIS. A guide to 

good practice 

(ADS, 1998) 

http://ads.ahds. 

ac.uk/project 

/goodguides/gis 

/index.html
graphics (e.g. 

to represent 

maps)

Objects principle 5. A good object will be named with a 

persistent, unique identifier that conforms to a well-documented 

scheme. It will not be named with reference to its absolute 

filename or address (e.g. as with URLs and other Internet 

addresses) as filenames and addresses have a tendency to change. 

Rather, the filename's location will be resolvable with reference to 

its identifier.

How an object is identified determines how (even whether) it may 

be found and thus made accessible over both the short and longer 

terms. There are at least two approaches to the provision of 

persistent and unique object identifiers. The first involves 

assigning identifiers that conform to a standard, and using 

applications that ensure that those names resolve to the object's 

filename and location. 

Where application of national and international standards is 

beyond an institution's technical capabilities (as it is likely to be at 

most smaller and even medium-sized institutions), a more local 

approach may be considered. This involves developing and 

maintaining a local scheme that uniquely identifies information 

objects, and mechanisms for ensuring that names resolve to file 

locations. Where local schemes are used they should be 

documented and documentation should be accessible. 

A third, middle way that is appropriate for Internet accessible 

objects is available by assigning PURLs (Persistent URLs) instead 

of URLs. The PURLs embedded in references to the object are 

resolved to true locations by a server which contains tables 

mapping PURLs to URLs. Although the mapping tables must be 

updated when an object is moved, this degree of indirection 

facilitates maintenance by ensuring each PURL need only be 

updated once in a central spot, no matter how many times it 

occurs in references. 

The following sites contain information about standard numbers: 

● International Standard Book Number system (ISBN). 

http://www.isbn.spk-berlin.de/

● Digital Object Identifier. http://www.doi.org

● International Standard Serial Number (ISSN). 

http://www.issn.org/index-eng.html

● Serial Item and Contribution Identifier. 

http://sunsite.berkeley.edu/SICI/

For information about the Persistent Uniform Resource Locator 

(PURL) see http://www.purl.org/. 
For more information about Uniform Resource Names (URNs) 

see http://www.ietf.org/html.charters/urn-charter.html

For information about the application of naming schemes see 

● "Handle Server", Library of Congress (1998) http://lcweb2.

loc.gov/ammem/award/docs/handle-server.html supplying 

a description of the Library's experiments using "handles," 

one form of URN 

● Harvard University Library Office for Information 

Systems, "Naming and Repository Services. An 

Introduction" http://hul.harvard.edu/ldi/resources/

nrsdrsservice.pdf. A detailed introduction to these services 

as supplied by the Office for Information Systems and 

including a useful gentle description of the importance and 

design of naming services, good practices, etc. 

● Harvard University Library Office for Information 

Systems, "Name Resolution Service (NRS) Technical 

Overview", (2000) see http://hul.harvard.edu/ldi/resources/

nrs-overview-public.html. Supplies a technical overview 

for the Name Resolution Service (NRS) developed by the 

Library Digital Initiative at Harvard University Library. 

The NRS is a comprehensive service for creating, 

maintaining, and resolving names, which are persistent, 

location-independent identifiers for network-accessible 

resources. 

Objects principle 6. A good object can be authenticated in at least 

two senses. First, a user should be able to determine the object's 

origins, structure, and developmental history (version, etc.). 

Second, a user should be able to determine that the object is what 

it purports to be. 

Being able to authenticate an object is essential for a number of 

reasons. Research is predicated on verifiable evidence. Teaching 

and learning, as well as other forms of cultural engagement, also 

rely on verification, although it is more frequently thought of in 

terms of a user's ability to assess an information object's veracity, 

accuracy, authenticity, even worth. There are some cases where 

verification takes on additional significance, as for example, with 

the networked representation of information that supplies 

evidence about important past or current events. 

Typically, information necessary for a user to determine an 

object's origin, structure, and developmental history is included 

with the metadata that is supplied for and about that object (see 

METADATA). 

Determining the veracity of a digital object is likely to rely upon 

techniques that are known but whose reliability is still debated. 

Techniques appropriate to digital images may include digital 
signatures and water marking. Checksums and other technical 

routines that produce message digests are appropriate for objects 

in virtually all formats. They help determine by analyzing the 

object's structure and composition whether it has been changed in 

any way since some particular benchmark point. 

Information may be found at 

● Authenticity in a Digital Environment (CLIR, 2000). 

Report of a group of experts convened by CLIR to address 

the question: What is an authentic digital object? http://

www.clir.org/pubs/reports/pub92/contents.html

● The importance of verifying the authenticity of an 

information object is well described in The Evidence in 

Hand: Report of the Task Force on the Artifact in Library 

Collections (2001) http://www.clir.org/activities/details/

artifact-docs.html

● MD5 unofficial home page http://userpages.umbc.edu/

~mabzug1/cs/md5/md5.html

● On checksum see http://www.checksum.org/

● On digital signatures see http://www.w3.org/DSig/ and 

information from the Electronic Privacy Information 

Center

● On digital watermarking see The information hiding 

homepage. Steganography and digital watermarking http://

www.cl.cam.ac.uk/~fapp2/steganography/

Objects principle 7. A good object will have and be associated 

with metadata. All good objects will have descriptive and 

administrative metadata. Some will have metadata that supplies 

information about their external relationships to other objects (e.

g. the structural metadata that determines how page images from 

a digitally reformatted book relate to one another in some 

sequence).

The Philadelphia Art Museum reports some 300,000 unique items 

in its collection. None of those objects would be of any use to 

anyone if the PMA did not also retain for each of its objects 

information about what it is, where it is located, when it was 

created, and similar information. Digital objects without metadata 

would be equally useless. 

This principle does not prescribe what metadata will be supplied. 

This issue is another where fitness for purpose comes into play. 

Nor does it assume how metadata will be related to objects. Some 

objects will have metadata embedded within them (such as an 

encoded text with an XML header; an image with a TIFF header). 

With others, metadata will be stored and managed separately, as 

another digital object in fact. 
For more information see METADATA. 

METADATA

One of the most challenging aspects of the digital environment is 

the identification of resources available on the Web. The existence 

of searchable descriptive metadata increases the likelihood that 

collections will be discovered and used. Collection-level metadata 

is addressed in the COLLECTIONS section of this document. 

This section addresses the description of individual objects and 

sets of objects within collections. 

Metadata is defined as "data about data" or "information about 

information". Anne Gilleland-Swetland, in Introduction to 

Metadata : Pathways to Digital Information (http://www.getty.edu/

research/institute/standards 

/intrometadata) states, "Perhaps a more useful 'big picture' way of 

thinking about metadata is as 'the sum total of what one can say 

about any information object at any level of aggregation.'" 

Gilleland-Swetland goes on to note that there are three basic kinds 

of metadata: 

● Content, which relates to what the object contains or is 

about, and is intrinsic to an information object. 

● Context, which indicates the who, what, why, where, and 

how aspects associated with the object's creation and is 

extrinsic to an information object. 

● Structure, which relates to the formal set of associations 

within or among individual information objects and can be 

intrinsic or extrinsic. 

These types of metadata are commonly known as descriptive, 

administrative and structural, respectively. Descriptive metadata 

helps users find objects, distinguish one object from another, and 

know something about objects they have found. Administrative 

metadata helps collection managers keep track of objects for such 

purposes as file management, rights management and 

preservation. Structural metadata can be thought of as the glue 

that binds compound objects together, relating, for example, 

articles, issues and volumes of serial publications, or the pages 

and chapters of a book. 

A primary reason for digitizing collections is to increase access to 

the resources held by the organization. Creating broadly 

accessible metadata is a way to maximize access by current users 

and attract new user communities. Examples of metadata systems 

include library catalogs, archival finding aids, and museum 

inventory control or registrar systems. Over the years, metadata 

formats have been developed for a wide range of digital objects. 

Within this range of formats, there is a degree of consistency 

across all metadata schemes that supports interoperability. For 
example, most if not all schemes provide for a title field, date 

field, and identifier field. It is important that cultural heritage 

institutions explore the metadata standards that are being adopted 

within their field, as well as across the broader cultural heritage 

environment, to assure the greatest likelihood of interoperability. 

There is usually a direct relationship between the cost of metadata 

creation and the benefit to the user: describing each item is more 

expensive than describing collections or groups of items, using a 

rich and complex metadata scheme is more expensive than using a 

simple metadata scheme, applying standard subject vocabularies 

and classification schemes is more expensive than assigning a few 

keywords, and so on. The decisions of which metadata standard(s) 

to adopt, what levels of description to apply, and so on must be 

made within the context of the organization's purpose for 

digitizing the collection, the users and intended usage, approaches 

adopted within the community, and the desired level of access. 

Questions to consider include, but are not limited to: 

● What type of cultural heritage institutions will be involved 

in the project? 

● What subject discipline will be involved? 

● What is the format of the original resources? 

● Is there an existing metadata system used by the 

organization? 

● Are the materials organized as a collection? 

● Does information exist that supports detailed description of 

the object? 

● Should the source object be described, or the digital 

version of it? 

Principles applying to good metadata: 

Metadata Principle 1: Good metadata should be appropriate to 

the materials in the collection, users of the collection, and 

intended, current and likely use of the digital object. 

There are a variety of published metadata schemes that can be 

used for digital objects, Web sites, and e-resources. There will 

often be more than one scheme that could be applied to the 

materials in a given collection. The choice of scheme should 

reflect the level of resources the project has to devote to metadata 

collection, the level of expertise of the metadata creators, the 

expected use and users of the collection, and similar factors. 

Organizations should consider the granularity of description, that 

is, whether to create descriptive records at the collection level, at 

the item level, or both, in light of the desired depth and scope of 

access to the materials. They should also consider which schemes 

are commonly in use among similar organizations; using the same 

metadata scheme will improve interoperability among collections. 
The International Federation of Library Association site Digital 

Libraries: Metadata Resources is a clearinghouse of metadata 

schemes. http://www.ifla.org/II/metadata.htm 

A good general introduction to metadata issues for cultural 

heritage institutions is Introduction to Metadata: Pathways to 

Digital Information (Murtha Baca, ed.) 

http://www.getty.edu/research/institute/standards 

/intrometadata/index.html

The following are examples of the major schemes in use in 

cultural heritage institutions. Links to toolkits, tutorials, 

implementation software, and examples of projects that have 

adopted the standards are included in addition to links to the 

standards. 

● Dublin Core: A simple generic element set applicable to a 

variety of digital object types. Dublin Core has been 

adapted by a number of communities to suit their own 

needs (such as the CIMI application profile for the 

museum community), and incorporated into a number of 

domain-specific metadata schemes. 

● Dublin Core Initiative: http://dublincore.org

● Open Archives Initiative application of Dublin Core http://

www.openarchives.org

● The CIMI Guide to Best Practice for museums using 

Dublin Core http://www.cimi.org/public_docs/

meta_bestprac 

_v1_1_210400.pdf

● The GEM (Gateway to Educational Materials) application 

of Dublin Core http://www.geminfo.org/Workbench/

Metadata/

● IMS: A complex metadata scheme for educational 

resources developed by the IMS Global Learning 

Consortium, Inc., a group with heavy commercial 

participation from major hardware and software vendors. 

http://www.imsproject.org/metadata/

● EAD: Encoded Archival Description is set of rules for 

designating the intellectual and physical parts of archival 

finding aids so that the information can be searched, 

retrieved, displayed and exchanged. EAD is written in the 

form of a Standard Generalized Mark-up Language 

(SGML) Document Type Definition (DTD). 

● EAD: http://lcweb.loc.gov/ead/

● The EAD Cookbook by Michael Fox http://jefferson.

village.virginia.edu/ead/ 

cookbookhelp.html

● SAA. EAD Working Group. Encoded Archival 

Description Application Guidelines. SAA, 1999. 

● Research Libraries Group recommended application 
guidelines for EAD. http://www.rlg. 

● Online Archives of California recommended application 

guidelines for EAD. http://www.cdlib.org/about/

publications/ 

oacbpg-2001.pdf

● A case study of using EAD with image navigation 

software. http://www.library.uiuc.edu/ahx/ead/tech/

CILMarch 

2001.ppt

● MARC: MARC is a long established standard within the 

library community for exchanging cataloging information. 

MARC supports the Anglo-American Cataloging Rules 

and is maintained by the Anglo-American library 

community. Over the last several years, MARC has been 

enhanced to support descriptive elements required of 

electronic resources. 

● MARC: http://lcweb.loc.gov/marc/

● Library of Congress. Understanding MARC Bibliographic: 

Machine-Readable Cataloging. (5th Edition). http://lcweb.

loc.gov/marc/umb/

● MARC documentation: Extensive documentation is 

available at the LC site and at OCLC http://oclc.org

● Content Standard for Digital Geospatial Metadata: 

Developed by the Federal Geographic Data Committee, the 

CSDGM (FGDC-STD-001-1998) describes the content, 

quality, condition, and other characteristics of geospatial 

data. 

● FGDC: http://www.fgdc.gov/metadata/metadata.html

● Factbook: http://www.fgdc.gov/publications/documents 

/metadata/metafact.pdf

● Tutorials: http://www.fgdc.gov/metadata/metatut.html

● Global Information Locator Service: A standard developed 

to describe government information resources, generally at 

the collection or agency level, but also usable at the item 

level. 

● GILS: http://www.gils.net/

● U.S. National Archives and Records Administration 

(NARA). Guidelines for the Preparation of GILS Core 

Entries. http://www.ifla.org/documentslibraries/cataloging 

/metadata/naragils.txt

● See also NARA Bulletin 95-3. http://www.ifla.org/

documentslibraries/cataloging/ 

metadata/bull95-3.txt

● DDI Codebook: A standard for representing 

"codebooks" (descriptions of social science datasets) in 

XML. Developed by the Data Documentation Initiative 

(DDI), a collaborative project of the social science 

community. 

● DDI homepage: http://www.icpsr.umich.edu/DDI/

● VRA Core Categories: The Visual Resources Association 
has developed a scheme for the description of art, 

architecture, artifacts and other visual resources. Now in 

version 3, the Core Categories were designed with the 

awareness that there are often multiple representations of a 

work of art, such as the original painting and a slide of the 

painting used in teaching. 

● VRA Core Categories, version 3 http://www.gsd.harvard.

edu/~staffaw3/vra/ 

vracore3.htm

● The VRA Data Standards Committee page http://www.gsd.

harvard.edu/~staffaw3/vra/ 

datastandardscomm.htm

Metadata principle 2: Good metadata supports interoperability. 

Teaching, learning and research today operate in a distributed 

networked environment. Identifying resources that are distributed 

across the world's college and university libraries, archives, 

museums and historical societies is extremely difficult. Cultural 

heritage institutions must design their metadata systems so that 

they support the interoperability of these distributed systems. 

Use of standard metadata schemes facilitates interoperability by 

allowing metadata records to be exchanged and imported into 

other systems that support the chosen scheme. Most standards 

schemes have also been mapped to other schemes. These 

mappings, or crosswalks, help users of one scheme to understand 

another, can be used in automatic translation of searches, and 

allow records created according to one scheme to be converted by 

program to another. If a locally created metadata scheme is used 

in preference to a standard scheme, a crosswalk to some standard 

scheme should be developed. 

● The Getty Standards Program maintains crosswalks 

relevant to art, architecture and cultural heritage 

information on their Metadata Standards Crosswalks page 

http://www.getty.edu/research/institute/standards/ 

intrometadata/3_crosswalks/index.html. 

● The Library of Congress maintains crosswalks to and from 

MARC (http://lcweb.loc.gov/marc/marcdocz.html). 

● The NSDL Standards Working Group has a metadata 

resources page largely devoted to crosswalks. 

http://128.253.121.110/NSDLmetaWG/IntroPage.html

One way to increase interoperability is to support the metadata 

format and harvesting protocol of the Open Archives Initiative. 

Systems that support OAI can expose their metadata to harvesters, 

allowing their metadata to be included in large databases and used 

by external search services. http://www.openarchives.org/
Another way to increase interoperability is to support protocols 

for cross-system searching. Under this model, the metadata 

remains in the source repository, but the local search system 

accepts queries from remote search systems. The best know 

protocol for cross-system search is the international standard 

Z39.50 http://lcweb.loc.gov/z3950/agency/. 

Metadata principle 3. Good metadata uses standard controlled 

vocabularies to reflect the what, where, when and who of the 

content. 

Content should be expressed in a standard form selected from 

standard lists. Examples of controlled vocabularies, include 

standard subject heading lists (e.g. Library of Congress Subject 

Headings), thesauri (e.g. the Art & Architecture Thesaurus) and 

taxonomic lists (e.g. TRITON, Taxonomy Resource and Index to 

Organism Names). Locally defined vocabularies, where 

appropriate, can be utilized. Classification systems (e.g. Dewey 

Decimal Classification) can also be used to provide subject 

access. Vocabularies should be consistently applied and the 

application documented. 

Controlled vocabularies, thesauri and classification systems 

available in [sic] the WWW lists several dozen web-accessible 

controlled vocabularies by subject area. http://www.lub.lu.se/

metadata/subject-help.html. 

The High Level Thesaurus Project (HILT) is a clearinghouse of 

information about controlled vocabularies, including related 

resources, projects, and an alphabetical list of thesauri. http://hilt.

cdlr.strath.ac.uk/Sources/index.html

The Getty Vocabulary Programbuilds, maintains, and 

disseminates several thesauri for the visual arts and architecture: 

Art & Architecture Thesaurus® (AAT) http://www.getty.

edu/research/tools/vocabulary/aat/

● Union List of Artist Names® (ULAN) http://www.getty.

edu/research/tools/vocabulary/ulan/

● Getty Thesaurus of Geographic NamesTM (TGN)http://

www.getty.edu/research/tools/vocabulary/tgn/

Some other controlled vocabularies: 

● Library of Congress Subject Heading List-Available 

through OCLC, RLG and other cataloging services and on 

CD ROM from the Library of Congress. 

● Medical Subject Heading List: http://www.nlm.nih.gov/

meshhom.html
● Thesauri of Graphic Materials I: http://lcweb.loc.gov/rr/

print/tgm1/

● Thesauri of Graphic Materials II: http://lcweb.loc.gov/rr/

print/tgm2/

● Thesaurus of Graphic Names: http://www.gii.getty.edu/

vocabulary.tgn.html

Metadata principle 4. Good metadata includes a clear statement 

on the conditions and terms of use for the digital object. 

Terms and conditions of use include legal rights (e.g. fair use), 

permissions and limitations. The user should be informed how to 

obtain permission for restricted uses, and how to cite the material 

for allowed uses. Special technical requirements, such as the 

required viewer or reader should also be noted 

If this information is the same for all the materials in a collection, 

documenting it in collection-level metadata is adequate (see 

COLLECTIONS). Otherwise metadata records for individual 

objects should contain information pertaining to the particular 

object. Many metadata schemes have designated places to put this 

information; if they do not, some locally-defined element should 

be used. 

Metadata principle 5: Good metadata records are objects 

themselves and therefore should have the qualities of good 

objects, including archivability, persistence, unique identification, 

etc. Good metadata should be authoritative and verifiable.

Metadata carries information that vouches for the provenance, 

integrity and authority of an object. Metadata's own authority 

must be established. Clues to the authority of a metadata record 

include the identification of the institution that created it and what 

standards of completeness and quality were used in its creation. 

The institution should provide sufficient information to allow the 

user to assess the veracity of the metadata, including how it was 

created (automated vs. manually created), what standards/schemes 

were used, and what vocabularies were used. 

The problem of non-authentic and inaccurate metadata is real and 

serious. Many Internet search engines deliberately avoid using 

metadata embedded in HTML pages because of pervasive 

problems with spoofing (one organization supplying misleading 

metadata for a resource belonging to another organization) and 

spamming (artificially repeating keywords to boost a page's 

ranking). The same techniques used to verify the integrity and 

authenticity of digital documents (e.g. digital signatures) can also 

be applied to metadata (see OBJECTS). 

6. Good metadata supports the long-term management of objects 

in collections.
Administrative metadata is information intended to facilitate the 

management of resources. It can include data such as when and 

how an object was created, who is responsible for controlling 

access to or archiving the content, what control or processing 

activities have been performed in relation to it, and what 

restrictions on access or use apply. Technical metadata, such as 

capture information, physical format, file size, checksum, 

sampling frequencies, etc., may be necessary to ensure the 

continued usability of an object, or to reconstruct a damaged 

object. Preservation metadata is a subset of administrative 

metadata aimed specifically at supporting the long-term retention 

of digital objects. It may include detailed technical metadata as 

well as information related to the rights management, 

management history, and change history of the object. 

The Dublin Core Metadata Initiative proposed but never finalized 

a simple set of administrative data elements. Despite the 

unfinished and unapproved nature of the work, some 

implementers have found it useful. http://metadata.net/admin/draftiannella-admin-01.txt

Two of the most widely reviewed preservation metadata element 

sets are the National Library of Australia's Preservation Metadata 

for Digital Collections (http://www.nla.gov.au/preserve/pmeta.

html) and the RLG PRESERV element set (http://www.rlg.org/

preserv/presmeta.html). 

The PADI (Preserving Access to Digital Information) 

clearinghouse at (http://www.nla.gov.au/padi) has a long 

annotated listing of resources related to preservation metadata at 

http://www.nla.gov.au/padi/topics/32.html. 

The Digital Imaging Group's DIG35 Specification: Metadata for 

Digital Images. Version 1.0, August 30, 2000 (http://www.

digitalimaging.org/) specifies technical metadata for images 

created by digital cameras. A draft NISO standard under 

development, Data Dictionary for Technical Metadata for Digital 

Still Images (http://www.niso.org/DataDict.html) focuses on 

images created by scanning. 

Structural metadata relates the pieces of a compound object 

together. If a book consists of several page images, it is clearly not 

enough to preserve the physical image files; information 

concerning the order of files (page numbering) and how they 

relate to the logical structure of the book (table of contents) is also 

required. Most schemes for recording structural metadata are local 

to a given institution or application. There is, however, an 

emerging standard that provides a framework for encoding 

descriptive, administrative, and structural metadata called the 
Metadata Encoding and Transmission Standard (METS) http://

www.loc.gov/standards/mets/. 

PROJECTS

Projects are initiatives of finite duration, designed to accomplish a 

specific goal. Often a grant application contains the project plan, 

which is begun when the grant is awarded and ends when grant 

funding runs out. With good luck and good planning, this is 

coterminous with the accomplishment of the objectives of the 

project. However, it is important to distinguish between the 

project, which is transient, and the collection, which in most cases 

should persist. If the intent is for the collection to be maintained 

after the end of the project period, plans must be made for 

incorporating collection maintenance into the normal operating 

procedures of the responsible institution. 

Projects to build digital collections often involve a crossdisciplinary subset of one institution's staff, but may also involve 

representatives from multiple institutions. Different people will 

contribute different skills and perspectives. However, it is 

important that there be one individual who is responsible for 

coordinating the work of all project participants and maintaining 

the project plan and timeline. The project manager may report to a 

higher manager, to a board of directors, or to an advisory board. 

However, the project manager should have the authority to 

delegate work, make decisions, and take remedial actions within 

the parameters set by the higher agency. 

Projects principle 1: A good project has a substantial design 

component.

Design includes all aspects of project planning, from processing 

workflow to the ultimate look and feel of the collection website. A 

realistic assessment of the functional requirements of users needs 

to be a key element in design. Some early projects are notorious 

for devoting major resources to sophisticated display functionality 

when their users mostly wanted printed documents. 

The Washington State Library Digital Best Practices site has a 

section on Project Management with a focus on market research 

as a tool for both design and promotion. http://digitalwa.statelib.

wa.gov/newsite/projectmgmt/index.htm. The Colorado 

Digitization Alliance provides an example of the identification of 

market segments and their varying needs. http://coloradodigital.

coalliance.org/users.html

RLG/DLF Guides to Quality in Visual Resource Imaging: 1. 

Planning an Imaging Project. http://www.rlg.org/visguides/

visguide1.html
Northeast Document Conservation Center. Handbook for Digital 

Projects: A Management Tool for Preservation & Access. III: 

Considerations for Project Management. http://www.nedcc.org/

digital/dighome.htm

Projects principle 2: A good project has an evaluation plan.

The IMLS encourages outcomes-based evaluation for their funded 

projects, and points to supporting resources. http://www.imls.gov/

grants/current/crnt_obe.htm. A generic Basic Guide to OutcomesBased Evaluation for Nonprofit Organizations with Very Limited 

Resources is available at http://www.mapnp.org/library/evaluatn/

outcomes.htm. 

The University of Texas has received an IMLS grant to develop 

tools and guidelines that libraries, museums and other information 

agencies can use to evaluate and improve the utility of their 

websites. http://imls.lib.utexas.edu/

Projects principle 3: A good project produces a project report.

The primary goal of any project should be to accomplish its stated 

objectives within the time and budget allowed. However, the 

knowledge gained in implementing a digital collection should not 

be lost to other organizations. Although most funding agencies 

require some sort of report at the end of the project period, these 

are not always generally available. A project report providing a 

detailed description and honest assessment of work accomplished 

should be produced and remain accessible on the Web 

indefinitely. 

Some examples of useful, comprehensive project reports: 

● Library of Congress. Manuscript Digitization 

Demonstration Project. Final Report. October 1998. http://

lcweb2.loc.gov/ammem/pictel/

● Anne R. Kenney Digital to Microfilm Conversion: A 

Demonstration Project 1994-1996. Final Report to the 

National Endowment for the Humanities PS-20781-94. 

http://www.library.cornell.edu/ 

preservation/com/comfin.html 

● Preserving and Digitizing Plant Images: Linking Plant 

Images and Databases for Public Access. November 2000. 

Final report from the Missouri Botanical Garden to the 

IMLS. http://ridgwaydb.mobot.org/mobot/imls/final.asp

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