Instantiation: Empirical Emergence of a Global Phenomenon

Richard P. SmiragliaPalmer School of Library and Information

Science, Long Island University, Brookville New York 11548 USA

CIDOC-CRM Workshop, ICS-FORTH, Heraklion, Crete, October 23-24, 2006

Meta-[huh?]-data

• Metadata for resource description are usually derived via either pragmatic or rational epistemologies

• I mean, they’re usually made up, sometimes based on experience

• Knowledge extraction via empirical research yields more accurate depictions

• Instantiation, which turns out to be a near universal phenomenon among informing objects (artifacts), is an exemplary case

Classificatory Functions of Metadata • Often are used as alphabetico-classed segments

of thesauro-faceted strings for information retrieval.

• Multiple instantiations must be collocated (i.e., caused to appear to be adjacent), with sufficient information to assist in the selection of the instantiation of interest to a searcher.

• To date, the only solution—a pragmatic solution—has been the uniform title—an alphabetico-classifier relying on linear sequence in an index file.

The Role of Empiricism--Research

• Empirical research is not always the method of choice in KO.

• Developments are technology driven (Hjorland 2003).• Therefore little is theoretically justifiable.• Data modeling—deriving metadata—requires empirical

evidence (Greenberg 2005)

The act of ‘naming’

• The act of naming facilitates use– Documents, artifacts, records

• Rationalized schema limit use by limiting retrieval• Base point for metadata schema should be empirical

observation of content itself– Allow content-creators a role in determining use– Directly, or,– Indirectly through empirical observation.

This brings us to—Instantiation

• “Instantiation,” essentially, is a generic term for the phenomenon of realization in time.

• “Version” implies deliberation in the creation of the phenomenon, also alteration.

• “Manifestation” implies physicality (manus being the Latin root for “hand”).

• Instantiation is a simpler term, used to signal a place in a sequence in time, but without these other implications of intellectual or physical detail. The term frees us to describe sets of multiply realized phenomena at an abstract level.

Undisambiguated Metadata[!]

Dickens, Charles. Great expectations.

Dickens, Charles. Great expectations.

Dickens, Charles. Great expectations.

Dickens, Charles. Great expectations.

Dickens, Charles. Great expectations.

Dickens, Charles. Great expectations.

• Error to assume these entities are identical

• Rather, their metadata representations (based on a rational schema) make them appear to be identical

• The entities actually represent points along a continuum, where the work has been instantiated

• These are called derivations• The farther from the point of

origin we get the greater the likelihood we have alteration of semantic or ideational content

• These are called mutations• Let’s look at some evidence

Terracotta hut urn

Terracotta hut urn

Terracotta hut urn

Terracotta hut urn

Terracotta hut urn

Terracotta hut urn

….

Bibliographically Speaking

• Instantiation is a phenomenon of bibliographic relationships among works; the cause-celebre of FRBR.

• An instantiation of a work exists whenever the work is realized in time (such as a performance or a reading), or when it is manifest in physical form (in a book, for example).

• A problem arises when multiple instantiations of a work (several editions, translations, etc.) exist and must be collocated in a retrieval system with sufficient information to assist in the selection of the instantiation of interest to a searcher

Empirical Evidence - 1

• 1. The majority of works exist in only one instantiation, but substantial proportions (associated in quantitative terms loosely with Lotka’s law) generate instantiation networks through mutation and derivation over instantiations over time.

• The ‘work’ apart from its carrier, is identified as ideational and semantic content. It is this content that evolves as the work instantiates.

• Instantiation with little change is called ‘derivation’ (e.g., editions).• Instantiation with change is called ‘mutation’ (e.g., adaptation).

Smiraglia, Richard P. 2002a. Further progress in theory in knowledge organization. Canadian journal of information and library science 26 n2/3: 30-49.

Empirical Evidence - 2

• 2. Simultaneous and successive editions, and translations, predominate among the types of mutation and derivation observed. Works that are likely eventually to be at the center of large instantiation networks are published simultaneously. Evolution of the network begins with successive editions and translations. Other types of instantiation are much less prevalent. And,

Empirical Evidence - 3

• 3. Older progenitors are associated with the largest instantiation networks. Regression coefficients demonstrate a consistent but relatively weak growth rate among instantiation networks such that, for evolving networks, the longer the time-span the greater the number of instantiations will appear.

Artifactually Speaking

• Similarly, unique artifacts can be re-presented by metadata or images (called representations), which can exist in multiple instantiations (a photographic negative, a print, its digital descendent, etc.).

• The same is true of the re-presentations of archival documents, which might exist in paper photocopies, digital images, and so forth.

The Integration of Cultural Information

• Museums, archives, and libraries share a common purpose, which is the dissemination of human culture.

• For knowledge sharing, the concept of “a work”—although the nature of a “work” is such that any artifact might be said to embrace (or contain) a work (or elements thereof)—must be embraced to account for diverse representation.

From Documents to Artifacts, From Instantiation to Content Genealogy

• Content genealogy is a generic term for relationships among generations of instantiations of an artifact.

• “Re-presentation” (hereafter rendered simply as “representation”) of objects (fine art, natural science) clearly precedes instantiation.

• The epistemology of the documentary work (as a communicating cultural entity) can be extended as a pragmatic tool for the development of metadata and other documentation practices for knowledge-sharing about works across domains.

Representation Taxonomy—Meta-level

ArtifactMetadataRepresentation

Instantiation

MetadataMaterialTypeItem numberSourceDate

RepresentationURL

Instantiation …

MATERIAL ARTIFACT SOURCE DATE URL

Etrusco-Corinthian Olpe Vulci, Tomb B 6th c. BCE daily.shtml

Impasto Footed bowl Narce, Tomb 19M

7th c. BCE faliscan.shtml

Bucchero Kantharos Vulci, Tomb B 6th c. BCE technology.shtml

Terracotta Hut urn Albano-Genzano

8th c. BCE earliest.shtml

Terracotta Antefix/Satyr Head Caere (Cervetari)

4th c. BCE architecture.shtml

Alabaster Cinerary urn 3 c. BCE final.shtml

Impasto Kotyle Narce, Tomb I 7th c. BCE orientalizing.shtml

Nenfro Lintel Orvieto 550 BCE language.shtml

Eight Etruscan Artifacts http://www.museum.upenn.edu/new/worlds_intertwined/etruscan/main.shtml

A Representation Taxonomy—In Repository

Artifact Metadata

Finding aidField notesLettersConservation

treatment notes

Register Object cards

Image order invoicesMuseum databaseCatalog

Representation  Field photosDrawingsWorking images3D modelsExhibition color images

Digitized imagesConservation photosPhoto archives negatives prints transparenciesObject reproductions

All Artifacts Have BothArtifact Metadata Representatio

nEtrusco-Corinthian Olpe X XFooted bowl X XKantharos X XHut urn X XAntefix/Satyr Head X XCinerary urn X XKotyle X XLintel X X

Artifacts and Representations: Totals

Artifact Representations

in house

Representations

in publication

Metadata In house Metadata

In publication

Etrusco-Corinthian Olpe

Wb,LS1,LS2,Ng1,Ng2,Ng3,Ng4,Ng5,CRp

Gu,GS,Do,DC

AC,OR,AR,CRp,LR,

Wb

Ex,DC

Footed bowl Wb,FN,Cy,Ng

Do,Gu

AC,OR,AR,FN,LR,Wb

Ex,DC,Do,

Kantharos Wb,FN,Cy,Ng

Gu

AC,OR,AR,FN,LR,Wb

Ex,DC

Hut urn Wb

MB’33,Gu

AC,OR,AR,CRc,Wb

Ex,

Antefix/Satyr Head Wb,FN,Cy,Ng,CRp

AJA’24,MB’33,Gu

AC,OR,AR,FN,CRc,Wb

Ex,Lu,AJA’24

Cinerary urn Wb,CRp1,CRp2,CRp3,FN,Cy,Ng

Gu

AC,OR,AR,Wb,CRp,FN

Ex,Lu,Tr,Ba,Fb,Pa

Kotyle Wb,FN,Cy,Ng

Gu

AC,OR,AR,Wb

Ex, Do

Lintel Wb

Gu

AC,OR,OR,IR,AR,Wb

Ex,

Artifacts and Representations: Field

NotesArtifact Representations

in house

Representations

in publication

Metadata In house Metadata

In publication

Etrusco-Corinthian Olpe

Wb,LS1,LS2,Ng1,Ng2,Ng3,Ng4,Ng5,CRp

Gu,GS,Do,DC

AC,OR,AR,CRp,LR,

Wb

Ex,DC

Footed bowl Wb,FN,Cy,Ng

Do,Gu

AC,OR,AR,FN,LR,Wb

Ex,DC,Do,

Kantharos Wb,FN,Cy,Ng

Gu

AC,OR,AR,FN,LR,Wb

Ex,DC

Hut urn Wb

MB’33,Gu

AC,OR,AR,CRc,Wb

Ex,

Antefix/Satyr Head Wb,FN,Cy,Ng,CRp

AJA’24,MB’33,Gu

AC,OR,AR,FN,CRc,Wb

Ex,Lu,AJA’24

Cinerary urn Wb,CRp1,CRp2,CRp3,FN,Cy,Ng

Gu

AC,OR,AR,Wb,CRp,FN

Ex,Lu,Tr,Ba,Fb,Pa

Kotyle Wb,FN,Cy,Ng

Gu

AC,OR,AR,Wb

Ex, Do

Lintel Wb

Gu

AC,OR,OR,IR,AR,Wb

Ex,

Artifacts and Representations: Signifying

objectsArtifact Representations

in house

Representations

in publication

Metadata In house Metadata

In publication

Etrusco-Corinthian Olpe

Wb,LS1,LS2,Ng1,Ng2,Ng3,Ng4,Ng5,CRp

Gu,GS,Do,DC

AC,OR,AR,CRp,LR,

Wb

Ex,DC

Footed bowl Wb,FN,Cy,Ng

Do,Gu

AC,OR,AR,FN,LR,Wb

Ex,DC,Do,

Kantharos Wb,FN,Cy,Ng

Gu

AC,OR,AR,FN,LR,Wb

Ex,DC

Hut urn Wb

MB’33,Gu

AC,OR,AR,CRc,Wb

Ex,

Antefix/Satyr Head Wb,FN,Cy,Ng,CRp

AJA’24,MB’33,Gu

AC,OR,AR,FN,CRc,Wb

Ex,Lu,AJA’24

Cinerary urn Wb,CRp1,CRp2,CRp3,FN,Cy,Ng

Gu

AC,OR,AR,Wb,CRp,FN

Ex,Lu,Tr,Ba,Fb,Pa

Kotyle Wb,FN,Cy,Ng

Gu

AC,OR,AR,Wb

Ex, Do

Lintel Wb

Gu

AC,OR,OR,IR,AR,Wb

Ex,

Artifacts and Representations: Non-

functionalArtifact Representations

in house

Representations

in publication

Metadata In house Metadata

In publication

Etrusco-Corinthian Olpe

Gu,GS,Do,DC

Ex,DC

Footed bowl Do,Gu

Ex,DC,Do,

Kantharos Gu

Ex,DC

Hut urn MB’33,Gu

Ex,

Antefix/Satyr Head AJA’24,MB’33,Gu

Ex,Lu,AJA’24

Cinerary urn Gu

Ex,Lu,Tr,Ba,Fb,Pa

Kotyle Gu

Ex, Do

Lintel Gu

Ex,

Representation Analysis

• The Etrusco-Corinthian Olpe and the Alabaster Cinerary Urn have the most representations and instantiations (the Satyr head is close)

• Field notes had no effect• Presence in the exhibit had no effect• The Alabaster Cinerary Urn and the

Nenfro Lintel have informative content—signification had no effect

Canonicity Strikes Again

• Conservationist Lynn A. Grant:– “We have ‘Frequent Flyers’—once an

object is published it gets requested for loan, photos are requested, etc. “ [even if the museum has better items in its collections]

– “Such items spend more time on loan than in the museum.”

Forms of Metadata In-House

Sources• Field Notes • Accession Ledgers• Object Records• Conservation

Records• Conservation

Reports• ARGUS Records

Data Types• Object entities• Activity-based

descriptors

Comparative In-House Metadata Schema

Object Records Schema Object numberLocalityCulture or PeopleDescriptionPhotoDimensionsCollectedPurchasedCataloguedConserved

Conservation Report Schema Accession Num.DepartmentGeneral DescriptionDrawing or Photo Entry DateConservatorExit DateExit LocationReason for EntryPreviews Records, Photos Observations, Condition Photographic Record:DateFilmViewAnalysis, Sampling Record:DateDescriptionTreatment RecordDateDescription

Conservation Record Schema Accession NoSectionObject: type material culture source collector date acquiredDimensionsEntry DateExit DateConservatorExit LocationReason for EntryOther RecordsDescriptionCondition:Treatment RequiredPhotographic RecordDateFilmViewsTreatment

Loan Record Schema Schedule of ObjectsAccession NumberDollar ValueDescriptionNameMaterial,WeightProvenienceCultureDateSizeSpecial Care Requirements

Object Condition Report Schema Loan NumberDateBorrowerDurationOutgoing reportIncoming Report Accession #ObjectConditionConfirmation of Condition

Accession Ledger (handwritten) [Subsequent number]Orig.No.Name & MaterialLocalityMeas.DateNo Spec.DescriptionWhen CollPaidDonor

Metadata Structure: Entity and Activity

Object Entity: type material culture source collector date acquired

Accession

Catalogue

ConservationCondition

Loan

Photographs

Semantic content of ‘object card’ is embedded in evolving metadata sets: successive and amplification derivation

Metadata Analysis

• The semantic “object entity” (“work” or “content” of the artifact) is represented consistently by the data set: type, material, culture, source, collector, date acquired

• The image ‘representation’ is multiply instantiated (simultaneous, successive derivation)

• Metadata representations are without authority control• Each division of the museum functions as an independent

work-based ecology*, generating its own metadata taxonomy

*Albrechtsen. 2000. Dynamism and stability … information ecologies

Conclusions-Artifactual

• Artifacts have in-house representations at a fairly predictable rate based on internal museum functions

• Artifacts have in-house instantiations and external representations at a variable rate based on the “popularity” or “canonicity” of the artifact

• Canonicity, in this case, is a function of publication not exhibit

• The object entity has a stable and consistent metadata set

• Specific ecologies within the museum contribute varying but related metadata sets

Drawing the Analogy for Artifacts

• Artifacts can constitute sets of representations, from which subsequent instantiation networks develop.

• All artifacts had in-house representations produced at a predictable rate based on internal museum functions.

• Original representations became centers of instantiation networks as copies were themselves copied, to be shared among divisions.

• Divergence in the instantiation networks, both their extent in number and the diversity of instantiation, appeared to be a function of the recognized popularity of the artifact.

Moving forward with the concept of instantiation (Oxford English Dictionary Online)• “The action or fact of instantiating; representation

by an instance.” • An instantiation exists empirically as a

representative of an information object.• A representation takes shape at a specific point in

time—an instant—as the result of an action. • An instant is “an infinitely short space of time; a

point of time; a moment.” • The locus of an instantiation is found along a

temporal trajectory, a potential plethora of instantiations might emerge.

Routledge Encyclopedia of Philosophy

• Instantiation takes the form of evidence.• Existential: ‘o has P’—‘there is at least one

[object] that has P.’• Universal: rule permits conclusion that any object

o has the property P from the premise that everything has P.

• Inference: signifying an argument or a step in an argument, or the process of passing from belief in the premises to belief in the conclusion.

• Quantifier: syncategorematic operators such as ‘all,’ ‘some,’ ‘none.’

Epistemological Parameters

• Instantiation is possessing the properties that define the object (its essence).

• The set of instantiations of an object can be defined empirically by the truth or untruth of ‘is a’ relationships.

• Instantiation proceeds from an object—whether abstract in nature, like a bibliographic work, or concrete, like an extant artifact—which object provides a historicist anchor in its identity.

• These identity anchors constitute nodes in information retrieval systems.

Catalytic Influence yields Instantiation

• Ii is a realization in time—an instantiation—of information object Oi and the potential set of instantiations of that object might run from Ii – n.

• The catalytic influence lends a breathless quality of urgency to the creation of instantiations.

• They are not haphazard but rather they result from some demand close to the object of origin and at least hypothetically occur at more widely spaced points over time as the trajectory recedes temporally.

Epistemological Summary

• ‘Instantiation’ is conceptually a part of any theory of object representation, predominantly those of “the work,” “the artifact,” or ‘the document.”

• That point at which a given realization takes form, and, in the presence of an appropriate catalyst, around which a network of representatives might cluster.

• Such clusters have been called “instantiation networks.”

Harmonizing ‘Works’ and ‘Representations’

• Instantiation—the evolution and reproduction of representations—is observed in both domains.

• Canonicity, which seems to contribute to the size of instantiation sets in the bibliographic domain, is mirrored in the artifactual domain by a kind of “popularity.”

• At a meta-level, cultural acceptance of a work or an artifact creates public demand for more representations.

Smiraglia, Richard P. 2004b. Content metadata—an analysis of Etruscan artifacts in a museum of archeology. Cataloging & classification quarterly (at press).

Consistent Elements of ‘Instantiation’

• 1) the universality of instantiation in all domains of knowledge objects;

• 2) the concept of cultural catalyst as a predictor of instantiation; and,

• 3) the influence of time as a predictor of the degree of instantiation

Archival documents

• Can the concept of instantiation be extended to unprocessed, raw data, as in the case of archival evidence?

• The U.S. Merchant Marine Academy at Kings Point, Long Island, New York--Class of 1942 archives

• Fourteen “folders” created by members of the class, and created for the purpose of leaving an historical record of the class.

One midshipman’s memorabilia

• Green canvas sectional post binder by Walcott-Taylor Co. Washington DC.

• Binder issued b y U.S. Maritime Commission designed for filing orders and official communications … heavy enough to jettison overboard should the need arise.

• Contents cover high school graduation to completion of merchant marine training in 1942.

Typical Contents

• Scan of postcard with photo of SS [ship]; scan of photo of foredeck; scan of photos of classmates aboard

• Original photo; same photo on postcard; scan of postcard photo

• Letter and MMA application; acceptance

• “Deck Log Abstracts” original• Time sheets

Correspondence

• Letters in typescript and in carbon; and scanned

• Scan of contents of register on CD

Instantiation is abundant in just one case

• photocopies, carbon copies, digitized scans of postcards containing photographs, scans of photos, photos alongside digitized scans of them, and documents together with their carbon copies and digitized scans of the originals

Knowledge Organization Tenets

• There is no single, uniform, universal description of instantiation such that a book represents a work.

• Rather, the eventual constitution of an instantiation network is domain- and culturally-sensitive.

• The phenomenon is universal among information objects. • History, past and future, determines the extent and depth

of the network and the relationships, semantic and ideational, among the nodes.

• For information retrieval it is important to grasp the centrality of the historic nodes of instantiation within each set.

• The nodes once catalyzed are roughly hierarchical.

The Simplest Set

• For every information object Oi the possibility of instantiation is present; some catalytic influence results in instantiation Ii for the simplest set

Oi → Ii

• an edition of a book, a photocopy of a document, a photograph of an artifact

A Basic Instantiation Network

• A set of instantiations from Ii – n for the common set 

Oi → Ii-n

• many editions of a book over time, or many photocopies of a document, or photographs of an artifact produced repeatedly from a negative image.

Catalytic Influence

• Culturally sensitive—not haphazard but resulting from some demand close to the object of origin and at least hypothetically occurring at more widely spaced points over time as the trajectory recedes temporally.

• A work popular in the time of its origin in multiple editions, recedes for centuries, a cultural shift “rediscovers” it, new sets of instantiations are generated

Nodes Within the Network

• In this case we have instantiation nodes within the set, from which instantiation networks can also proceed for the set

Oi → Ii-n Iii-n Iiii- n

• Where each Ii is a new instantiation node. At each node n is the sum of the is (hence the extent of the instantiation network), and Ix is the representative of a node of instantiation.

Example: Bibliographic Work 1

• William of Ockham Tractatus de praedestinatione et de

praescientia Dei et de futuris contingentibus.Bologna 1496. • 1945 - Philotheus Boehner’s ed. with commentary based on mss. and 1496

printing. St. Bonaventure, NY: Franciscan Institute, St. Bonaventure College• 1969 - English translation with commentary by Marilyn McCord Adams and

Norman Kretzmann. New York: Appleton-Century-Crofts• 1978 - Contained, edited by Boehner, in vol. 2 of “Works.” St. Bonaventure,

N.Y.: St. Bonaventure Univ.• 1983 - 2nd ed. of Adams-Kretzmann translation; hard copy and paper ISBNs.

Indianapolis: Hackett Pub. Co.• 1994 - issued as text computer file from 1978 “works” now called v. 10.

Turnhout: Brepols.• 1988 - Perler Ger. trans. with commentary. Amsterdam: BR. Gruner• 1992 - microform of 1945 ed. Notre Dame, Ind.: Univ. of Notre Dame

Example: Bibliographic Work 2

• William of Ockham Tractatus de praedestinatione et de

praescientia Dei et de futuris contingentibus.Bologna 1496. O1 → I1 1496 ed.

I1(1) 1945 tr

(1) 1978 ed.

(2) 1994 cf

I1(2) 1969 tr.

(1) 1983 ed.

I1(3) 1988 tr.

Example: Artifact 1Etrusco-Corinthian OlpeImages in-house:

Digital image on websiteLantern slide 1, Negative 1Lantern slide 2, Negative 2Negatives 3, 4, 5Conservation Report

Images (and metadata descriptions) published:Digital image in Guide to Etruscan …Print of LS1 in Gottfried-Semper 1985, in Dickinson College Etruscan pottery 1984, Dohan Italic tomb groups 1942 and [mf] 1973

Metadata in-house:Accession record, Object record, Archives, Conservation Report, Loan Report, Website and in the Exhibit

Example: Artifact 2-Images• Etrusco-Corinthian Olpe

O2 → I1 LS1(1)NG1

(1) Photo

(1) GS

(2) DC

(3) DO

(1) mf

(2) Digitized

(1) wb

(2) GU

I2 LS2(2)NG2

I3-5 NG3-5

I4 (CRp)

Example: Archival Entity• U.S. Merchant Marine Academy-Class of 1942 Archives• Battle of the Atlantic

-Correspondence with A and B ’61-Archivists copy of the folder-Digitized copy of the folder

O3 → I1 folder

(1) archivists copy

(2) digitized copy

Three Instantiation Sets

O1 → I1 1496 ed.

I1(1) 1945 tr

(1) 1978 ed.

(2) 1994

cf

I1(2) 1969 tr.

(1) 1983

ed.

I1(3) 1988 tr.

O3 → I1

folder

(1)

archivists

copy

(2)

digitized

copy

O2 → I1 LS1(1)NG1

(1) Photo

(1) GS

(2) DC

(3) DO

(1) mf

(2) Digitized

(1) wb

(2) GU

I2 LS2(2)NG2

I3-5 NG3-5

I4 (CRp)

Lacunae

• FRBR refers to instantiation as “expression” and “manifestation,” and sequences them temporally, such that an expression must exist before its manifestation.

• Logically, this is the same action represented here as instantiation of an information object.

• Empirically we see that there are two types of instantiation that are not particularly temporally distinct: mutation and derivation.

• The nodes are culturally sensitive, are not necessarily sequential, and might be nested.

• Logical application of the phenomenon of instantiation to the evolution of documentary content across physical formats (say from paper to microform to digital form) is possible (i.e. content genealogy)

Bibliographic Taxonomy Typology

• simultaneous editions; successive editions; translations; amplifications; extractions; adaptations; and, performances (Smiraglia 1992)

• Predecessor; accompanying material (Smiraglia and Leazer 1999)

• Musical presentation; notational transcription (Vellucci 1997)

• Persistent works (Smiraglia Forthcoming)

• Terms represent properties, not mutually exclusive categories

• A translation may be amplified, etc.

Comparative Instantiation Typologies

Bibliographic Works Artifacts—Metadata Artifacts—Representations Personal Papers

Simultaneous editions Finding aids Field photos Photocopies

Successive editions Field notes Working images Carbon copies

Predecessors Letters Exhibition color images Photos

Amplifications Conservation treatment notes Digitized exhibition images Postcard with photo

Extractions Register descriptions; object cards

Conservation photos Digitzed scan of postcard with photo

Accompanying materials Image order invoices Archived photgraphic negatives Reprint of photo

Musical presentation Museum database records Archived photographic prints Digitized scan of photo

Notational transcription Catalog card records Archived photographic transparencies

Persistent works Finding aids

Mutations Mutations

Translations Object reproductions

Adaptations Drawings

Performances 3D models

Typology Naïve classification

• Terms in the typologies discover and fill gaps in knowledge about instantiation, reconstruct empirically derived evidence, facilitate integration of findings (Beghtol 2003)

Empirical Derivation

• Pan- and inter-institutional digital libraries incorporate representations of documentary, artifactual, and archival information resources.

• Instantiation enriches the resource base, but threatens chaos in retrieval.

• Empirical derivation of instantiation typologies suggests a realistic approach to metadata solutions.