Working PaperResearch Highlights: Cataloging Theory in Search of Graph Theory and Other Ivory Towers.

Object: Cultural Heritage Resource Description NetworksRonald J. Murray and Barbara B. Tillett

A research project by Library of Congress (LC) staff is bringing cataloging theory into the

21st Century by infusing powerful ideas from the sciences and or mathematics. Barbara Tillett

(Chief of the Policy and Standards Division, Acquisitions and Bibliographic Access

Directorate) and Ronald Murray (a Digital Conversion Specialist in the Preservation

Reformatting Division) are reexamining institutionally-centered resource description

processes – called “cataloging” in Cultural Heritage institutions (libraries, archives, and

museums). Instead of designing data formats and databases for data/metadata collection like

technologists pursuing bottom-up World Wide Web and Semantic Web initiatives, Tillett and

Murray are taking a complementary, top-down, approach.

They are investigating how catalogers, other Cultural Heritage information workers,

World Wide Web/Semantic Web technologists, and the general public have understood,

explained, and managed their resource description tasks by creating, counting, measuring,

classifying, and otherwise arranging descriptions of Cultural Heritage resources within the

Bibliographic Universe and beyond it. The project grew out of Murray’s 2003 graduate

Communication Theory research, which treated libraries as nodes in communications

networks. Now the two focus on describing what enlargements of cataloging theory and

practice are required such that catalogers and other interested parties can describe pages from

unique, ancient codices as readily as they might describe information elements and patterns

in the World Wide Web.

1

Tillett and Murray enhance cataloging theory with concepts from Communications Theory,

History of Science, Graph Theory, Computer Science, and from the hybrid of Anthropology

and Mathematics called Ethnomathematics. Their development and dispersion of advanced

resource description theories and practices is intended to benefit two groups:

Workers in the Cultural Heritage realm, who will acquire a broadened perspective on

their resource description activities, who will be better prepared to handle new forms

of creative expressions as they appear, and will also be able to shape the development

of information systems that support more sophisticated types of resource descriptions

and ways of exploring those descriptions. Note: To build a better bookshelf (perhaps

an n-dimensional, n-connected bookshelf?), one needs better theories about shelves

and the people or groups who stock and choose from them.

The full spectrum of people who draw upon Cultural Heritage resources: scholars,

and other creatives (novelists, poets, visual artists, musicians, etc.), professional &

technical workers, and; K-12, undergraduate, graduate and post-graduate learners,

and other persons or groups in pursuit of specific or general, long- or short-term

interests, entertainment, etc.

Tillett and Murray argue that applying a multidisciplinary perspective to the processes by

which resource description “data” (linked or otherwise) is created and used is not an Ivory

Tower exercise. Their approach draws lessons from the very intensive debates that were

conducted by physicists, engineers/software developers, and their historian and philosopher

of science observers during the evolution of High-Energy Physics.1 The debates covered

theory and observational/experimental data, roles of theorists, experimenters, and instrument

builders, instrumentation, and over hardware/software system design.

2

Noting that these physics research facilities are the same ones whose scientific subcultures

(theory, experiment, and instrument building) generated the data creation, management,

analysis, and publication requirements that resulted in the World Wide Web, Tillett and

Murray assert that Cultural Heritage resource description – i.e., the process of identifying and

describing phenomena in the Bibliographic Universe as opposed to the physical one ––

should be as open to the concepts and practices of 21st Century physics subcultures as it had

been to those of the natural sciences in the 19th Century.2 Instead of focusing on scientific

data management systems and the “mini resource description theories” used to construct

them, Tillett and Murray instead undertook an intensive study of the scientific subcultures

that generate scientific data – and identified four key principles upon which to base a more

general approach to resource description:

Observations

Complementarity

Graphs

Exemplars

The Cultural Heritage resource description theory being developed proposes a more

articulated view of the complex, collaborative process of making available – through their

descriptions – socially relevant Cultural Heritage resources at a global scale. A broader

understanding of this resource description process (and the ability to create improved

implementations of it) requires integrating ideas from other fields of study.

I. Cataloging as Observation

• Cataloging is a process of making observations on resources.

3

Tillett and Murray honor the scientific community for their outstanding success in describing

the (physical) Universe by introducing into the Bibliographic Universe the concept of an

observation:

The action or an act of observing scientifically; esp. the careful watching and noting of an

object or phenomenon in regard to its cause or effect, or of objects or phenomena in

regard to their mutual relations (contrasted with experiment). Also: a measurement or

other piece of information so obtained; an experimental result.3

Human or computational observers following institutional business rules (i.e., the terms,

facts, definitions, and action assertions that represent constraints on an enterprise and on

the things of interest to the enterprise4) create resource descriptions – accounts or

representations of a person, object, or event being drawn upon by a person, group,

institution, etc. in pursuit of its interests:

Figure 1. A Resource Description Modeled As A Business Rule-Constrained Account Of A Person,

Object, Or Event

Given this definition, a person (or a computation) operating from a business rules-generated

institutional or personal point of view, and executing specified procedures (or algorithms) to

do so, is an integral component of a resource description process. This process involves

identifying a resource’s textual, graphical, acoustic, or other features, and then classifying,

making quality and fitness for purpose judgments, etc. upon the resource. Knowing which

4

institutional or individual points of view are being employed is essential when parties

possessing multiple views on those resources describe Cultural Heritage resources. How

multiple resource descriptions derived from multiple points of view are to be related to one

another becomes a key theoretical issue with significant practical consequences.

II. Niels Bohr’s Complementarity Principle and the Library

Cultural Heritage resource descriptions can document multiple overlapping, and

complementary views on Cultural Heritage resources.

In recognizing the validity and value of multiple ways of describing bibliographic and other

resources, Tillett and Murray’s resource description theory pays homage to the physicist

Niels Bohr, who in 1927 posed a radical explanation for seemingly contradictory

observations of physical phenomena.5 According to Bohr, creating descriptions of nature is

the primary task of the physicist:

“It is wrong to think that the task of physics is to find out how nature is. Physics

concerns what we can say about nature.6”

Bohr’s complementarity principle states that a complete description of atomic-level

phenomena requires descriptions of both wave and particle properties. This is generally

understood to mean that in the normal language that physicists use to communicate

experimental results, the wholeness of nature is accessible only through the embrace of

complementary, contradictory, and paradoxical descriptions of it. Later in his career, Bohr

vigorously affirmed his belief that the complementarity principle was not limited to Quantum

Physics:

5

“In general philosophical perspective, it is significant that, as regards analysis and

synthesis in other fields of knowledge, we are confronted with situations reminding

us of the situation in quantum physics. Thus, the integrity of living organisms, and the

characteristics of conscious individuals, and most of human cultures, present features

of wholeness, the account of which implies a typically complementary mode of

description… We are not dealing with more or less vague analogies, but with clear

examples of logical relations which, in different contexts, are met with in wider

fields.7”

Within a library, there are many things catalogers, conservators, and preservation scientists –

each with their distinctive skills, points of view, and business rules – can say about Cultural

1 See “Part II: Building Data” in Peter Galison, Image & Logic: A Material Culture Of Microphysics (Chicago: University of Chicago Press, 2003), 370-431.

2 Exclusive control of classification schemes and of the records that named and described its specimens are said to have contributed to the success of the British Museum’s institutional mission in the 19th Century. Gordon McQuat, “Cataloguing Power: Delineating ‘Competent Naturalists’ And The Meaning Of Species In The British Museum,” The British Journal for the History of Science, 34, no. 1 (Mar., 2001), 1-28.

As a division of the British Museum, the British Library appears to have incorporated classification concepts (hierarchical structuring) from its parent and elaborated upon the Museum’s strategies for cataloging species.

3 “observation, n.”. OED Online. July 2011. Oxford University Press. http://www.oed.com/viewdictionaryentry/Entry/129883 (accessed 7/8/2011).

4 David C. Hay, UML And Data Modeling: A Vade Mecum For Modern Times (Bradley Beach NJ: Technics Press, Forthcoming 2011), 124-125.

5 Gerald Holton, “The Roots Of Complementarity,” Daedalus 117, no. 3 (1988): 151-197, accessed February 24, 2011, http://www.jstor.org/stable/20023980.

6 Niels Bohr, quoted in Aage Petersen, “The Philosophy Of Niels Bohr,” Bulletin of the Atomic Scientists 19, no. 7 (Sept. 1963): 12.

7 Niels Bohr, “Quantum Physics and Philosophy: Causality and Complementarity.” in Essays 1958-1962 on Atomic Physics and Human Knowledge (Woodbridge CT: Ox Bow Press, 1997), 7.

6

Heritage resources.8 Much of what these specialists say and do strongly impacts library users’

ability to discover, access, and use library resources in their original or surrogate forms. A

fuller appreciation of these resources calls for the integration of these multiple views – or

voices – into an articulated, accessible whole.

Reflecting Tillett’s and Murray’s joint LC Acquisitions and Bibliographic Access (ABA)

Directorate and Preservation Directorate worldview, the most fundamental complementary

views on Cultural Heritage resources involve describing a library’s resources in terms of

their information content – an iconic activity – and in terms of their physical properties – an

activity less well known. In the normal languages used to communicate their results,

Preservation Directorate conservators make condition assessments and record physical

measurements of items – while at the same time preservation scientists have instrumentation

are on hand to acquire optical and chemical data from submitted materials and from reference

collections of physical and digital media. Even though these assessments and measurements

may not be comprehensible by or accessible to most Library users, they possess a critical

logical relationship to bibliographic and other descriptions of those same resources. This is

because decisions regarding a resource’s fitness for purpose, it’s reformatting, and its long-

term preservation must take into account the physical characteristics of the resource.

Having things to say about Cultural Heritage resources – and having many “voices” with

which to say them – presents the problem of creating a well-articulated context for library-

generated resource descriptions as well as those from other sources. Murray and Tillett assert

that these contextualization issues must be addressed theoretically prior to implementation-

8 For cataloging theorists, the description of Cultural Heritage things of interest yields groups of statements that occupy different levels of abstraction. Upon regarding a certain physical object, a marketer describes product feature, a linguist enumerates utterances, a scholar perceives a work with known or inferred relationships to other works, etc.

7

level thinking, and that the demands of contextualization require visualization tools to

complement the narratives common to catalogers, scholars, and other users. This is where

mathematics and ethnomathematics make their entrance.

Ethnomathematics is the study of the mathematical practices of specific cultural groups over

the course of their daily lives and as they deal with familiar and novel problems.9 An

ethnomathematical perspective on Cultural Heritage resource description directs attention to

the construction of simple and complex resource descriptions, the patterns of descriptions

created, and the representation of these patterns when they are interpreted as expressions of

mathematical ideas. One advantage of operating from an Ethnomathematical perspective is

realizing that mathematical ideas can be expressed within a (sub)culture prior to their having

been identified and treated formally by Western-style mathematicians.

III. Resource Description as Graph Creation

Relationships between Cultural Heritage resource descriptions can be represented as

conceptually engaging and flexible, systems of connections mathematicians call Graphs.

The researchers argue that a full appreciation of key mathematical ideas underlying the

evolution of cataloging was only possible after the founding, naming, and expansion of one

field of mathematics (Graph Theory from the 1850’s on), and the eventual acceptance circa

1900 of Set Theory, a field founded amid intense controversy in 1874. Between the

emergence of this possibility and it’s actual exploitation by cataloging theorists – or by

anyone capable of considering library resource description and organization problems from a

mathematical perspective – rested a gulf of more than 100 years. It remained for scholars in

9 Marcia Ascher, Ethnomathematics: A Multicultural View of Mathematical Ideas (Pacific Grove, CA: Brooks/Cole Publishing Company, 1991). Marcia Ascher, Mathematics Elsewhere: An Exploration of Ideas across Cultures (Princeton: Princeton University Press, 2002).

8

the library world to begin addressing the issue. Notably, Tillett’s 1987 work on bibliographic

relationships10 and Svenonius’ 2000 definition of bibliographic entities in set-theoretic

terms11 identified mathematical ideas in cataloging theory and developed them formally. By

2009, Murray and Tillett proceeded to employ graph theory (expressed in set-theoretical

terms and in its highly informative graphical representation) as part of a broader historical

and cultural analysis.12

Cataloging theory had by 2009 haltingly embarked upon a new view on (a.) how resources in

libraries have been described and arranged via their descriptions – an activity which in

principle stretches back to catalogs in the Library of Alexandria,13 and (b.) how these

structured resource descriptions have evolved over time, irrespective of implementation.

Their investigations indicate that the increasingly formalized and refined rules that guided

Anglo-American catalogers had, by 1876, specified sophisticated systems of cross-references

(i.e., connections between bibliographic descriptions of works, authors, and subjects) –

systems whose characteristics were not the subject of formal mathematical treatment by

mathematicians of the time.14 Murray and Tillett found that library resource description

10 Barbara Tillett, “Bibliographic Relationships: Towards a Conceptual Structure of Bibliographic Information Used in Cataloging” (PhD. diss., University of California, Los Angeles, 1987).

11 As opposed to database implementations that permitted Boolean operations on records at retrieval time. For a set-theoretic treatment of bibliographic entities, see Elaine Svenonius, The Intellectual Foundation Of Information Organization (Cambridge, MA: MIT Press, 2000), 32-51.

12 http://www.slideshare.net/RonMurray/-the-graph-theoretical-library

13 Francis J. Witty, “The Pinakes Of Callimachus,” Library Quarterly 28, no. 1-4 (1958): 132-136.

14 Ronald J. Murray, “Re-Imagining The Bibliographic Universe: FRBR, Physics, And The World Wide Web,” Slideshare.net, last modified Oct 22 2010, http://www.slideshare.net/RonMurray/frbr-physics-and-the-world-wide-web-revised.

9

structures circa 1875 – when teased out of their book and card catalog implementations and

treated as graphs – are arguably more sophisticated than many employed in or proposed by

the World Wide Web Consortium’s (W3C) Library Linked Data initiative.15

Theory-Guided Implementation – The researchers note that cataloging theory has been both

helped and hindered by the use of Information Technology (IT) techniques like Entity-

Relationship modeling (E-R, first used extensively by Tillett in 1987 to identify bibliographic

relationships in cataloging records) and Object-Oriented (OO) modeling.16 They note that E-

R and OO modeling may be used effectively to create information systems from an inventory

of ‘things of interest’ and the relationships that exist among them. Unfortunately, the ‘things

of interest’ in Cultural Heritage institutions keep changing and may require redefinition

and/or aggregation. E-R and OO modeling as usually practiced are not designed to manage

the degree and kind of chances that take place.

Murray and Tillett assert that when trying to figure out what’s ‘out there’ in the

Bibliographic Universe, focus should first be placed on identifying and describing the things

of interest, what relationships exist among them, and what processes are involved in creation,

etc. of resource descriptions. Having accomplished this, attention can then be safely paid to

defining and managing information deemed essential to the enterprise (i.e., undertaking IT

system analysis and design). But if an IT-centric modeling technique becomes the bed upon

15 For an overview of the technology-driven Library Linked Data initiative, see http://linkeddata.org/faq. Murray and Tillett’s analyses of Cultural Heritage resource descriptions may be explored in a series of slideshows at http://www.slideshare.net/RonMurray/.

16 Pat Riva, Martin Doerr, and Maja Žumer, “FRBROO: Enabling a Common View of Information from Memory Institutions,” International Cataloging and Bibliographic Control 38, vol. 2 (June 2009): 30-34.

10

which the resource description theory itself is constructed, the resulting theory will be driven

in a direction that is strongly determined by the modeling technique.

Describing The Bibliographic Universe with Graphs

To appreciate their mathematical power and their many applications in the physical sciences,

engineering – and especially in Computer Science – the researchers shaped their

investigations into graph theory and its history17 to their perception of the needs of the

Cultural Heritage community. Ever since its 19th Century foundations (though scholars

regularly date its origins from Euler’s 1736 paper), and its move from the backwaters of

recreational mathematics to full field status by 1936, graph theory has concerned itself with

the properties of systems of connections – nowadays expressed in the form of the

mathematical objects called sets.18 In addition to its set notational form, graphs are also

depicted and manipulated in diagrammatic form as dots/labeled nodes linked by labeled or

unlabeled, simple or arrowed lines. For example, the graph X, consisting of one set of nodes

17 Dénes König, Theory Of Finite And Infinite Graphs, trans. Richard McCoart (Boston: Birkhaüser, 1990).

Fred Buckley and Marty Lewinter, A Friendly Introduction To Graph Theory (Upper Saddle River NJ: Pearson Education Inc., 2003).

Oystein Ore and Robin Wilson, Graphs And Their Uses. Washington DC: The Mathematical Association of America 1990.

Siriam Pemmaraju and Steven Skiena, Computational Discrete Mathematics: Combinatorics And Graph Theory With Mathematica.© (New York: Cambridge University Press, 2003).

18 “Set Theory, branch of mathematics that deals with the properties of well-defined collections of objects, which may or may not be of a mathematical nature, such as numbers or functions. The theory is less valuable in direct application to ordinary experience than as a basis for precise and adaptable terminology for the definition of complex and sophisticated mathematical concepts.”

Quoted from “Set Theory,” Encyclopædia Britannica Online. Oct 2010. Encyclopædia Britannica. http://www.britannica.com/EBchecked/topic/536159/set-theory (accessed Oct. 27 2010).

11

labeled A, B, C, D, E, and F and one set of edges labeled AB, BD, DE, EF, and FC, can be

depicted in set notation as X = {{A B C D E F}, {AB BD DE EF FC}} and can be depicted

diagrammatically as:

Figure 2. A Diagrammatic Representation Of Set X

When graphs are defined to represent different types of nodes and relationships, it becomes

possible to create and discuss structures that can support Cultural Heritage resource

description theory and application building. Like most forms of mathematics, graph theory’s

possibilities require restriction to the task at hand. Lacking a graph-theoretical approach

attentive to constraints and demands arising from and constrained by a tacit or explicit

resource description theory and/or practice, graph structures favored by an institution’s

system designers and developers – or those familiar to and favored by implementation-

oriented communities – may be invoked inappropriately.

The following diagrams depict simple resource description graphs based on real-world

bibliographic descriptions. Nodes in the graphs represent text, numbers, or dates and

relationships that can be unidirectional or bidirectional.

12

Figure 3. Library of Congress Catalog Data for Thomas Pynchon’s Novel Gravity’s Rainbow, Represented as an All-In-One Graph Labeled C

The all-in-one resource description graph in fig. 3 can be divided up and connected according

to the kinds of relationships that have been defined for Cultural Heritage resources. This is

the point where institutional, group, and individual ways of describing resources determine

the final structure of the graph. Once constructed, graph structures and their diagrammatic

representations are then further interpreted in terms of a tacit or explicit resource description

theory. In the case of graphs constructed to IFLA’s Functional Requirements for

Bibliographic Records standard,19 fig. 3 can be subdivided into four FRBR sub-graphs, to

yield fig. 4.

19 IFLA Study Group on the Functional Requirements for Bibliographic Records, Functional Requirements for Bibliographic Records: Final Report (München: K.G. Saur, 1998). This document is downloadable from http://www.ifla.org/VII/s13/frbr/frbr.pdf or as html: www.ifla.org/VII/s13/frbr/frbr.htm.

13

Figure 4. The All-In-One Graph in Figure 3, Separated Into Four FRBRWork, Expression, Manifestation, and Item Graphs

The four diagrams depict catalog data as four complementary FRBR W|E|M|I (W–Work, E–

Expression, M–Manifestation and I–Item) graphs. Note that the Item graph contains the call

numbers (used here to identify the location of the copy) of three physical copies of the novel.

This use of call numbers is qualitatively different from the values found in the Manifestation

graph, in that resource descriptions in this graph apply to the entire population of physical

copies printed on that occasion.

The descriptions contained in fig. 3’s FRBR sub-graphs reproduce bibliographic

characteristics found useful by catalogers, scholars, other educationally oriented end-users,

and to varying extents the public in general. Once created, resource description graphs and

sub-graphs (in mathematical notation or in simple diagrams like the above) can proliferate

and link in multiple and complex ways– in parallel with or independently of the resources

they describe. Figure 4’s diagrammatic simplicity becomes problematic when large quantities

of resources are to be described, when the number and kind of relationships recorded grows

large, and when more comprehensive but less detailed views of bibliographic relationships

are desired. To address these problems in a comprehensive fashion, Murray examined similar

situations in the sciences and borrowed another idea from the Physics community – Paper

Tools.

Paper Tools14

Paper tools are collections of symbolic elements (diagrams, characters, etc.), whose

construction and manipulation follow set rules and constraints.20 Berzelian chemical notation

(e.g., C6H12O6) and – more prominently – Feynman diagrams21 like those in fig. 5 are

examples of paper tools creation and use.

Figure 5. Feynman Diagrams Of Elementary Particle Interactions

Creating a paper tool requires that the rules for creating resource descriptions be reflected in

diagram elements, properties of diagram elements, and rules that define how

diagram/symbolic elements are connected to one another (e.g., the formula C6H12O6 specifies

six molecules of Carbon, twelve of Hydrogen, and six of Oxygen). For a FRBR paper tool,

the detailed bibliographic information in fig. 4 is progressively schematized in a way that

reflects FRBR definitions of bibliographic things of interest and their relevant relationships.

First, the four W|E|M|I descriptions in fig. 4 are given a common identity by linking them to

a C node, as in fig. 6.

20 Ursula Klein, ed., Experiments, Models, Paper Tools: Cultures Of Organic Chemistry In The Nineteenth Century, (Stanford CA: Stanford University Press, 2003).

Ursula Klein, ed., Tools And Modes Of Representation In The Laboratory Sciences, (Boston: Kluwer Academic Publishers, 2001).

David Kaiser, Drawing Theories Apart: The Dispersion Of Feynman Diagrams In Postwar Physics. (Chicago: University of Chicago Press, 2005).

21 For a more examples and an general description of Feynman diagrams see http://www2.slac.stanford.edu/vvc/theory/feynman.html

15

Figure 6. A FRBR Resource Description Graph

The diagram is then further schematized such that FRBR description types and relationships are

represented by appropriate graphical elements connected to other elements. For Murray, a FRBR

paper tool makes it much easier to construct and examine complex large-scale properties of resource

and resource description structures like fig. 7 (right side) without being distracted by text and link

detail.

Or

Figure 7. A FRBR Paper Tool Diagram Element (Left) and the Less SchematicFRBR Resource Description Graph It Depicts (Right)

The resource being described (but not shown) in the less schematic graph is represented

explicitly by a black dot in a circular slot by the more schematic paper tool version. Resource

descriptions are represented in fixed color and position relative to the resource/slot: the

Work-level resource description is represented by a blue box, Expression by a green box,

Manifestation by a yellow box, and Item by a red box. Depicting one aspect of the FRBR

model graphically, the descriptions closest to the black dot resource/slot are the most

concrete and those furthest away the most abstract. To minimize element use when pairs of

16

W|E|M|I boxes touch, the appropriate FRBR linking relationship for the relevant descriptions

(shown in the expanded graph) is implied but not shown.

With appropriate diagramming conventions, the process of exploring resource descriptions

complexes addressing combined issues of cataloging theory and institutional policy – results

in an ability to make better-informed judgments/computations about a resource description

and its referenced resource(s). Unlike most of their implemented counterparts, resource

description graphs are readily transformable to serve theoretical – and with greater

experience in thinking and programming along graph-friendly lines, practical – ends. One

example of this would be exploring the implications of removing redundant portions of

related resource descriptions as more copies of the same work are brought to the

Bibliographic Universe:

Copy #1

Or

+

Copy #2 At

Ft. Meade

Or

=

Or 17

Figure 8. FRBR Paper Tool Diagram Elements and the FRBR Resource Description Graphs They Depict

The FRBR paper tool and less schematic resource description graph in fig. 8 present the

results of a practical action: combining resource descriptions for two copies of the same

edition of the novel Gravity’s Rainbow.

Paper Tools, Exemplars, And Library Linked Data

With the four principles (observations, complementarity, graphs, and exemplars) to guide

them, Murray and Tillett are alert for opportunities to offer their informed approach and the

graph-based information structures they have identified or devised to guide the development

of future library information systems. The researchers assert that recent efforts by the W3C

Library Linked Data incubation group (LLD XG)22 to establish a historical context for its

data interoperability initiative can be an early beneficiary of their research.

The LLD XG initiative operates from an avowedly bottom-up, implementation-oriented

perspective – encouraging the reorientation of library metadata models, standards and

22 The Library Linked Data incubator group’s mission statement: “The mission of the Library Linked Data incubator group is to help increase global interoperability of library data on the Web, by bringing together people involved in Semantic Web activities—focusing on Linked Data—in the library community and beyond, building on existing initiatives, and identifying collaboration tracks for the future.

The group will explore how existing building blocks of librarianship, such as metadata models, metadata schemas, standards and protocols for building interoperability and library systems and networked environments, encourage libraries to bring their content, and generally re-orient their approaches to data interoperability towards the Web, also reaching to other communities. It will also envision these communities as a potential major provider of authoritative datasets (persons, topics...) for the Linked Data Web. As these evolutions raise a need for a shared standardization effort within the library community around (Semantic) Web standards, the group will refine the knowledge of this need, express requirements for standards and guidelines, and propose a way forward for the library community to contribute to further Web standardization actions.”

Quoted from “Library Linked Data Incubator Group Wiki,” World Wide Web Consortium, last modified July 1, 2011, http://www.w3.org/2005/Incubator/lld/

18

protocols, etc, towards those being developed for the Semantic Web.23 A report from this

group claimed success in having created library-relevant standards following the W3C

model,24 but lamented the perceived slow rate of adoption of Web-type technologies and

attitudes towards data collection and use.25 As part of their argument for speeding up the

adoption of the W3C’s Resource Description Format (RDF26), resource description standard,

they invoke Thomas Kühn’s concept of a paradigm:

23 The LLD Incubator Group defines library linked data as follows:

“Library. The word "library" (analogously to "archive" and "museum") refers to three distinct but related concepts: a collection, a place where the collection is located, and an agent which curates the collection and administers the location. Collections may be public or private, large or small, and are not limited to any particular types of resources.

Library data. "Library data" refers to any type of digital information produced or curated by libraries that describes resources or aids their discovery. Data used primarily for library-management purposes is generally out of scope. As discussed in more detail below, this report pragmatically distinguishes three types of library data based on their typical use: datasets, element sets, and value vocabularies.

Linked Data. "Linked Data" (LD) refers to data published in accordance with principles designed to facilitate linkages among datasets, element sets, and value vocabularies. Linked Data uses Web addresses (URIs) as globally unique identifiers for dataset items, elements, and value concepts, analogously to the library world's identifiers for authority control. Linked Data defines relationships between things; these relationships can be used for navigating between, or integrating, complementary sources of information.

Library Linked Data. "Library Linked Data" (LLD) is any type of library data that is either natively maintained, or merely exposed, in the form of RDF triples, thus facilitating linking.”

Quoted from “Draft Report With Transclusion,” Section Title: “Scope Of This Report,” World Wide Web Consortium, last modified June 10, 2011, http://www.w3.org/2005/Incubator/lld/wiki/DraftReportWithTransclusion#.22Library_Linked_Data.22:_Scope_of_this_report.

24 Ibid. Section title: “Bottom-Up Standards Can Be Successful But Garner Little Recognition.”

25 Ibid. Section title: “Libraries Do Not Adapt Well To Technological Change.” http://www.w3.org/2005/Incubator/lld/wiki/DraftReportWithTransclusion#Libraries_do_not_adapt_well_to_technological_change.

26 “Resource Description Framework (RDF),” RDF Working Group, last modified Feb 2, 2010, http://www.w3.org/RDF/.

19

“Translators of legacy library standards into Linked Data must recognize that

Semantic Web technologies are not merely variants of practices but represent a

fundamentally different way to conceptualize and interpret data. … digital data in

libraries has been managed predominantly in the form of ‘records’ -- bounded sets of

information described in documents with a precisely specified structure -- in

accordance with what may be called a Record Paradigm. The Semantic Web and

Linked Data, in contrast, are based on a Graph Paradigm. In graphs, information is

conceptualized as a boundless ‘web’ of links between resources … In the Graph

Paradigm, the ‘statement’ is an atomic unit of meaning that stands on its own and can

be combined with statements from many different sources to create new graphs -- a

notion ideally suited for the task of integrating information from multiple sources into

recombinant graphs.27”

27 The complete quote (spacing added) is: “Translators of legacy library standards into Linked Data must recognize that Semantic Web technologies are not merely variants of practices but represent a fundamentally different way to conceptualize and interpret data.

Since the introduction of MARC formats in the 1960s, digital data in libraries has been managed predominantly in the form of ‘records’ -- bounded sets of information described in documents with a precisely specified structure -- in accordance with what may be called a Record Paradigm.

The Semantic Web and Linked Data, in contrast, are based on a Graph Paradigm. In graphs, information is conceptualized as a boundless ‘web’ of links between resources -- in visual terms as sets of nodes connected by arcs (or ‘edges’), and in semantic terms as sets of ‘statements’ consisting of subjects and objects connected by predicates.

The three-part statements of Linked Data, or ‘triples,’ are expressed in the language of the Resource Description Framework (RDF). In the Graph Paradigm, the ‘statement’ is an atomic unit of meaning that stands on its own and can be combined with statements from many different sources to create new graphs -- a notion ideally suited for the task of integrating information from multiple sources into recombinant graphs.”

Quoted from “Library Data Must Be Conceptualized According To The Graph Paradigm,” World Wide Web Consortium, last modified June 10, 2011, http://www.w3.org/2005/Incubator/lld/wiki/DraftReportWithTransclusion#Library_data_must_be_conceptualized_according_to_the_Graph_Paradigm.

20

Tillett and Murray think that the LLD initiative has reached a key stage in its efforts. There is

clearly an interest on the part of LLD XG implementation-focused technologists to place

their data-oriented standards and software development program in a larger conceptual and

technical context. They framed the issue within a scientific context by calling upon a

common interpretation of Thomas S. Kühn’s work on the development of scientific theories

(i.e., “normal science,” “revolutionary science,” 28) to advance their “Record Paradigm” vs.

“Graph Paradigm” argument. Unfortunately, Kühn’s use of that term clouds the picture.

Which Paradigm?

The Library Linked Data incubator group invoked the term “paradigm” to imply a historical

process by which the “Record Paradigm” will (or should) be displaced by the “Graph

Paradigm.” From their analysis, the normal practice of conceptualizing and implementing

bibliographic information as records will/should be displaced by a revolutionary practice

involving conceptualization and implementation in RDF. This turns out that during a

conference focused on his ground-breaking work on scientific progress, historians and

philosophers of science criticized Kühn layering too many meanings – according to Elizabeth

Masterman, twenty-one29 – onto the word “paradigm.

Masterman then sorted Kühn’s senses of paradigm into three classes30 – each of which

happens to be relevant describing the current situation in Cultural Heritage institutions.

Interestingly, many of Kühn’s many meanings of the word were touched upon in the LLD

28 Thomas S. Kühn, The Structure Of Scientific Revolutions (Chicago: University of Chicago Press), 1962.

29 Margaret Masterman, “The Nature of a Paradigm,” in Criticism And The Growth Of Knowledge. International Colloquium In The Philosophy of Science, ed. Imre Lakatos and Alan Musgrave (New York: Cambridge University Press, 1970), 59-89.

21

XG report.31 Many of Kühn’s senses of the word engage institutional missions and

managerial issues, with a smaller quantity falling more naturally within the scope of a group

tasked with investigating data formats and related technologies.

Metaphysical Paradigms – Claims about new vs. old ways of seeing, critiques of

governing beliefs (towards catalogers, cataloging practices, and their data products)

fall into this category.

Sociological Paradigms – Attempts to determine and speed the rate of adoption of

Web innovations in the library world would collect here. Innovation adoption studies

in IT environments have been performed by business or sociologically focused parties

operating under a Diffusion of Innovations paradigm.32

Artifact Paradigms – Creation, update and/or replacement of classic cataloging

works, rulebooks, textbooks, and physical & mental tools constitute the most concrete

sense of the term. These are information products within which standards are defined

30 Masterman, ibid, 65-66.

31 Conceptual models, applying Semantic Web technology, workflows, data management, outreach, etc. Quoted From “Topics For LLD Discussion And Use Cases,” World Wide Web Consortium, last modified June 10, 2011, http://www.w3.org/2005/Incubator/lld/wiki/Topics.

32 Everett M. Rogers Diffusion of Innovations, 5th ed. (New York: Free Press. 2003). The sociologist Everett Rogers defined an innovation as any thing, concept, or event perceived as new within an organization or community. Social networks convey information about an innovation, with key roles having a critical effect on adoption.

Rogers also identified five perceived attributes of an innovation that determine its rate of adoption within an organization: relative advantage, comparability, complexity, trialability, and observability. The phrases “early adopter,” “late adopter,” and “barriers to adoption” come from Rogers’ research program. A review of empirical research on information technology diffusion has identified four innovation adoption contexts XXXX.

The LLD XG employs Diffusion of Innovations terminology in its report, but did not rate its own topic against the perceived innovation attributes listed above.

22

and documented and from which old and new data models, schema, etc., emanate and

contend. Creation, modification, and use of data structures, IT architectures, etc. that

implement cataloging/resource description rules involve data and application-focused

library world technologists in varying roles.

Exemplars, Not Paradigms – Kühn, acknowledging that the paradigm concept he introduced

had taken on a life of its own, continued to elaborate upon the runaway concept, but

introduced the concept of an Exemplar to describe what he meant the first time. To Kühn,

exemplars are sets of concrete problems and solutions encountered over the course of one’s

education, the solution of which requires mastery of relevant models, builds knowledge

bases, and hones problem-solving skills. Every student in a field is expected to demonstrate

mastery by engaging their field’s exemplars. with exemplars being added to the set as new

puzzles appear and are solved.

To Tillett and Murray, their program of identifying, developing, and making Cultural

Heritage resource description exemplars available for analysis and discussion reflects Kühn’s

original interest in describing how science is practiced, taught, and learned and how they

change over time. They seek results that can be implemented across differing technologiesA

collection of Cultural Heritage resource description exemplars developed and over time and

presented for study, mastery, improvement, and use would include treatments of familiar,

time-tested resources that had been innovative in their time:

A manuscript (individual and related multiples, published but host to history, imaginary, etc.)

A monograph in one edition (individual and related multiples)

A monograph in multiple editions (individual and related multiples)

A publication in multiple media, sequentially or simultaneously created23

more complex ones:

A continuing publication (individual and related multiple publications, special editions, name, publisher, editorial policy changes, etc.)

A library-hosted multimedia resource and its associated resource description network

A World Wide Web page and its underlying globally-distributed multimedia resource network, changing over time

and then proceed to very complex ones, as will be illustrated below.

Exemplars vs. Use Cases – As products of and guides for theory-making, resource

description exemplars have different origins and audiences than those for “use cases,” the

software modeling technique employed by the LLD XG33 in support of requirements

specification.

“A use case in software engineering and systems engineering, is a description of steps

or actions between a user (or ‘actor’) and a software system which leads the user

towards something useful. The user or actor might be a person or something more

abstract, such as an external software system or manual process… Use cases are

mostly text documents, and use case modeling is primarily an act of writing text and

not drawing diagrams. Use case diagrams are secondary in use case work.34”

The FRBR paper tool was developed specifically to allow a cataloging theorist or other party

employing FRBR-based cataloging rules to create and explore simple and complex resource

description structures from bibliographic data, as well as to define resource description

structures as part of a theoretical exploration. The use of diagrams in support of

33 Daniel Vila Suero, “Use Case Report,” World Wide Web Consortium, last modified June 27, 2011, http://www.w3.org/2005/Incubator/lld/wiki/UseCaseReport.

34 “Use Case,” Wikipedia, last modified June 13, 2011, http://en.wikipedia.org/wiki/Use_case.

24

conceptualization and information system design is deliberately patterned after professional

data modeling theory and practice.35 The things of interest described in Exemplars – after

conceptual and logical data modeling and then implementation take place – are represented

in part by data that is collected, managed, and manipulated by information systems.

Murray notes that a resource description theorist, in addition to creating exemplars from

real bibliographic data and other sources, would also want to be able to speculate

diagrammatically about possible resource/description configurations that will require

improvements in existing information technologies. For example, it is as important to find

out what can’t be done with the current FRBR model at library and Internet scales as it is to

explain routine cataloging or tagging activities. Discovering system limitations is better done

in advance by simulating uncommon circumstances than by having problems appear in

production systems.

Cultural Heritage Resource Description Exemplars As Problem Solution Sets

The FRBR paper tool’s flexibility is useful for exploring potentially complex bibliographic

relationships created or uncovered by scholars – parties whose expertise lies in identifying,

interrelating, and discussing creative concepts and influences across a full range of

communicative expressions. The work products of scholars – especially those creations that

are dense with quotations, citations, and other types of direct and derived textual and

graphical reference within and beyond themselves – are excellent environments for paper

tool explorations and exemplar fitness-for-purpose testing. They also pose real-world

challenges for designers of paradigm-shifting information systems. Exemplar-minded paper

tool explorations of scholarly treatments of a 19th Century American novel and of 18th

35 Graeme Simsion, Data Modeling: Theory and Practice (Bradley Beach NJ: Technics Press, 2007), 333.

25

Century French poems drawn from state archives are presented below to illustrate how

exemplar-based information system design and pedagogy can be informed by diagrammatic

representations of bibliographic and other relationships.

From Moby-Dick to Mash-Ups – A Publication History and Multimedia Mash-Up Exemplar

Problem: Document the publication history of print copies of a literary work, identifying

editorally driven content transfer across print editions, as well as content transformation in

support of multimedia resource creation.

Solution: After identifying a checklist for print edition publication and tracing key features

of a Moby-Dick and Orson Welles-themed multimedia resource appropriation and

transformation network, Murray used the FRBR paper tool and additional connection rules to

create a Resource Description Diagram (RDD) that represented a scholar’s documentation of

the printing history (from 1851 to 1976) of Herman Melville’s epic novel, Moby-Dick.36

36 Herman Melville, Moby-Dick (New York: Harper & Brothers; London: Richard Bentley 1851).

Moby-Dick edition publication history excepted from G. Thomas Tanselle, Checklist Of Editions Of Moby-Dick 1851-1976. Issued On The Occasion Of An Exhibition At The Newberry Library Commemorating the 125th Anniversary Of Its Original Publication (Evanston and Chicago: Northwestern University Press and The Newberry Library, 1976).

26

Figure 9. A Moby-Dick Resource Description Diagram, Depicting Relationships Between PrintingsMade Between 1851-1976 (Greatly Reduced Scale)

To reduce displayed complexity, sets of FRBR diagram elements were “collapsed” into green

shaded squares representing entire editions/printings, yielding fig. 9.37 Two or more lines

converging on a green square from above indicate that a printing was created by combining

parts of multiple texts – a technique similar to that of the mash-ups published on the World

Wide Web. Squares not linked to any others indicate that Tanselle had not established the

predecessors of the depicted editions – a condition which speaks to the benefits to be

acquired by exemplar-minded collaborative description and diagram creation.

When taken as scholarly documentation, Melville scholars, enthusiasts, and scholarly

organizations38 can examine, discuss and add to the diagram and increase its documentary

and educational (for scholars, etc.) value. The wealth of descriptive information available for

Moby-Dick in all its forms justifies divisions of labor among Cultural Heritage institutions

37 Ronald J. Murray, “From Moby-Dick to Mash-Ups: Thinking About Bibliographic Networks,” Slideshare.net, last modified April 2011, http://www.slideshare.net/RonMurray/from-moby-dick-to-mashups-revised. The Moby-Dick resource description diagram was presented to the American Library Association Committee on Cataloging: Description and Access at the ALA Annual Conference 2010 on July 2010.38 “The Life and Works of Herman Melville” The Life and Works of Herman Melville, last modified July 25, 2000, http://melville.org.

27

(to provide baseline structure and content), and parties who flesh out the structure with

general and specific content.

When promoted to exemplary problem-solution status by catalogers and others describing

similar resources, attention and discussion can shift on exemplar sufficiency, i.e., does it

solve the description problem by accommodating and structuring available information about

the resource? If, in the face of information flowing in from all quarters, the exemplar cannot

accommodate the variety of information known to benefit resource discovery, identification,

selection, navigation, etc., the opportunity then exists to modify or replace the exemplar with

one that does a better job. This more focused process of exemplar identification or creation

followed by modification, and replacement reflects Kühn’s and historian of science Kaiser’s

interests in how work gets done in the sciences, as well as their rejection of paradigms as

eerie self-directing processes.39

Extending Or Replacing Exemplars– In its original form, the Moby-Dick resource

description diagram (and the exemplar it implied) only covered complete printed publications

of Melville’s work. As a test of the FRBR paper tool’s ability to accommodate both

traditional and modern creative expressions in individual and aggregate form – while having

the result continue to serve theoretical, practical, and educational ends – Murray went on to

incorporate a resource description network for Alex Itin’s Moby-Dick-themed multimedia

mash-up, Orson Whales40 into the RDD. The four-minute long Orson Whales multimedia

mash-up contains hundreds of hand-painted page images from the novel, excerpts from a Led

Zeppelin song ‘Moby Dick,’ parts of two vocal performances by the actor Orson Welles, and

a video clip from Welles’ motion picture Citizen Kane. The result is shown in fig. 10.

39 Kaiser, 2005, 385-386.28

Figure 10. A Resource Description Diagram Of Alex Itin’s Moby-Dick Multimedia Work,Depicting The Resources And Their FRBR Descriptions.

The leftmost group of descriptions in fig. 10 depicts various releases of Led Zeppelin’s

musical work, “Moby Dick.” The central group depicts the sources of two Orson Welles

audio dialogues after they had been ripped (i.e., digitized from physical media) and made

available online. The grouping on the right depicts the Orson Whales mash-up itself and

collections of digital images of painted pages taken from two printed copies of the novel. The

layout and connectivity suggests a mechanism for navigating to the original resources from

any component of the mash-up.

Content in the custody in other Cultural Heritage institutions can also benefit from a paper

tool approach, provided things of interest and relationships between them can be defined

adequately.

40 The New York artist describes his creation: “It is more a less a birthday gift to myself. I've been drawing it on every page of Moby Dick (using two books to get both sides of each page) for months. The soundtrack is built from searching ‘moby dick’ on YouTube (I was looking for Orson's Preacher from the the [sic] John Huston film)... you find tons of Led Zep [sic] and drummers doing Bonzo and a little Orson... makes for a nice Melville in the end. Cinqo [sic] de Mayo I turn Forty. Ahhhhhhh the French Champagne.”

Quoted from Alex Itin, “Orson Whales,” YouTube, last modified Jan 2011, http://www.youtube.com/watch?v=2_3-gEm6O_g.

29

Poetry and The Police – An Archival Content Identification and Critical Analysis Exemplar

Problem: Examine archival collections and select, describe, and document ownership and

other relationships of a set of documents (poems) alleged to have circulated within a social

group.

Solution 1: In his 2010 work, Poetry and the Police: Communication Networks in

Eighteenth-Century Paris, historian Robert Darnton studied a 1749 Paris police investigation

into the transmission of poems highly critical of Louis XV. After combing state archives for

police reports, scraps of paper once held as evidence, and other archival materials, Darnton

was able to construct a poetry communication network diagram41 which, along with his

narrative account, identified the parties who owned, copied, and transmitted six scandalous

poems and placed their actions in a social and political context.

Solution 2: Darnton’s analysis treated each poem as a separate creative work,42 enabling the

use of the FRBR paper tool (as a bookkeeping device) instead of one designed to aggregate

and describe archival materials. Murray was able to devise a more articulated FRBR paper

tool version of the network. Figure 11 depicts part of the of the poetry communication

network.

41 Robert Darnton, Poetry And The Police: Communication Networks In Eighteenth-Century Paris (Cambridge MA: Belknap Press of Harvard University Press, 2010), 16.

42 Ronald J. Murray in a discussion with the author, Sept 20, 2010.

Darnton considered the poems retrieved from the archives as distinct intellectual creations –which permitted the use of FRBR diagram elements for the analysis. Otherwise, a paper tool with diagram elements based on the archival descriptive standard ISAD(G) would have been used. Committee on Descriptive Standards, “ISAD (G): General International Standard Archival Description,” (Stockholm, Sweden, 1999).

30

Figure 11. A Section Of Darnton’s Poetry Communication network

The FRBR paper tool version of the poetry communication network43 is composed of:

Tan squares that depict individuals (clerks, professors, priests, students, etc.) who

read, and discussed, copied and passed along the poems.

FRBR diagram elements that depict written poetry on scraps of paper (treated as

resources), in police custody, admitted to have existed by suspects, or assumed to

have existed by the police. Paper tool conventions can accommodate lost and

nonexistent but describable resources – if theory and business rules permit.

Arrowed lines that represent relationships between a poem and the parties who

owned copies, those who created or received copies of the poem, etc.

With Darnton’s monograph to provide background information regarding historical

personages involved, relationships between the works and the people, his document selection

from archival fonds, the above solution can first of all serve as enhanced documentation for

43 The complete poetry communication diagram may be viewed at: XXXXX31

Darnton’s analysis and discussion. It can then serve then as an exemplar for catalogers,

scholars, and others who want a solution to the problem of identifying, describing, and

discussing as individual works documents ordinarily grouped into archival fonds.

A Paper Tool Into a Power Tool

Murray notes that there are limits to what they can do with a hand-drawn FRBR paper tools.

While he was able to depict large-scale bibliographic relationships that probably had not

been observed before, he had to stop building the Moby-Dick diagram because he could not

put the useful information he had into a static, hand-drawn diagram. What he thinks is

needed is automated assistance in creating resource description diagrams from bibliographic

records. With that capability at hand, cataloging theorists and parties with scholarly and

pedagogical interests could more efficiently and interactively examine how scholars and

sophisticated readers describe significant quantities of analog and digital resources.

Murray asserts that it would be extremely useful to begin a scholarly discussion or a lecture

by saying “Given a Moby-Dick resource description network …” and then to be able to argue

or teach directly from a diagram depicting all copies of all printings of Moby-Dick – along

with all adaptations and excerpts – in a given Bibliographic Universe (such as the records

that appear in OCLC’s WorldCat bibliographic database). Resource description diagrams,

created from real-world or theoretically motivated considerations, would then provide a

diagrammatic means for depicting the precise and flexible underlying mathematical

representations that, heretofore unrecognized, serve resource description ends. If the structure

of a well-motivated resource description diagram makes requirements that an IT system

cannot handle all, cataloging theorists and information technologists alike will then know of

32

that system’s limitations and decide how to mitigate them and/or how to improve system

capabilities.

Cataloging Theory, Tool-Making, Education, And Practice

Tillett and Murray note that the resource description theory presented offers new and

enhanced roles and benefits for Cultural Heritage personnel as well as for the scholars,

students, and those members of the general public who require support not just for searching,

but also for collecting, reading, writing, collaborating, monitoring, etc.44 Information systems

that couple a modern, high-level understanding about how resources are described,

organized, and presented for exploration with data models that support multiple points of

view can support those requirements.

Tillett and Murray assert that what used to be called cataloging theory and practice –

disciplines that did not especially interest many outside of Cultural Heritage institutions – has

evolved into a much more comprehensive multilevel activity which can be approached with

at least two distinct points of view. The researchers consider their approach as providing a

cosmological-level view of the Bibliographic Universe. This perspective on existing or

imaginable large-scale configurations of Cultural Heritage resource descriptions is a

necessary complement to a quantum-level approach – characterized by IT-related

specificities such as character sets, identifiers, RDF triples, triplestores, etc. and enabling

powerful but unconstrained and theory information processing capabilities naïve to theory –

pursued by Semantic Web technologists. Murray asserts that both views – and actions taken

in pursuit of those views – are essential for progress. He notes in the history of physics is

44 Carole L. Palmer, Lauren C. Teffeau, and Carrie M. Pittman, Scholarly Information Practices For The Online Environment: Themes From The Literature And Implications For Library Science Development (Dublin OH: OCLC Research, 2009), http://www.oclc.org/programs/publications/reports/2009-02.pdf.

33

brightly illuminated by mutually influential interactions of cosmological- and quantum-level

theories, practices, and pedagogy – and that workers in Cultural Heritage institutions and

technologists pursuing World Wide Web Consortium initiatives would do well to reflect on

that finding.

Ready for the Future – And Creating The Future

Tillett and Murray assert that exploring the cultural, scientific, and mathematical ideas

underlying Cultural Heritage resource description, the identification, study, and teaching of

exemplars, and exploiting the theoretical reach and bookkeeping capability of their paper tool

(or of ones created by their colleagues) pay homage to the Cultural Heritage community’s

170+ year-old talent for pragmatic, implementation-oriented thinking while pointing out a

rich set of possibilities for future service. The community can draw inspiration from

geometrician Bernhard Riemann’s justification for thinking outside of the box:

“The value of non-Euclidean geometry lies in its ability to liberate us from preconceived

ideas in preparation for the time when exploration of physical laws might demand some

geometry other than the Euclidean.45”

Taking Riemann to heart, Murray asserts that the value of describing Cultural Heritage

resources as observations organized into graphs, and of attending to the exemplars that have

evolved over time and circumstance lies in their potential to liberate the Cultural Heritage

community from preconceived ideas about resource description structures and points of view

on those resources. Having achieved that goal, the Cultural Heritage community would then

be ready when the demand came for resource description structures that are more flexible and

powerful than the traditional ones. Mindful of the unprecedented development of the World

45 G.F.B. Riemann quoted in Marvin J. Greenberg, Euclidean And Non-Euclidean Geometry: Development And History (New York: W.H. Freeman and Company, 2008), 371.

34

Wide Web and the promise of Semantic Web initiatives, Tillett and Murray think that the

time for Cultural Heritage community’s liberation is at hand.

35