2. © Tefko Saracevic, Rutgers University1 metadata considerations for digital libraries

3. © Tefko Saracevic, Rutgers University2 the Web fastest growing technology in history explosive growth of WWW provided –ubiquity of information and access –but also information chaos & anarchy growing difficulty in identifying, searching & retrieving ‘lost in an ocean’ metaphors

4. © Tefko Saracevic, Rutgers University3 problem to organize & search the Web needed: knowledge about the structure of data –but Web data & databases fuzzy –structures vary widely; no consistency –constantly evolve over time –lack of agreement about meaning of even simple terms & concepts in structure

5. © Tefko Saracevic, Rutgers University4 solution some standardized description or language to increase functionality –a mechanism for a more precise description of things on the Web going from machine-readable to machine-understandable –missing in original Web architecture METADATA !

6. © Tefko Saracevic, Rutgers University5 metadata

7. © Tefko Saracevic, Rutgers University6 what? metadata: ‘data about data’ –machine understandable information for the Web - emphasis on machine –description of what a text (or any object) part is all about e.g. labeling title, author, source … many evolving standards suggested to be applied in various domains

8. © Tefko Saracevic, Rutgers University7 where? in volatile digital environments –metadata describe electronic resources, texts & multimedia –metadata exist or have meaning only in relation to the referenced document or object provide information about the object

9. © Tefko Saracevic, Rutgers University8 why? to standardize description of what is what in electronic resources in order to aid in identification, organization, & location of a great variety to enable effective search of variety of objects (documents) distributed all over sometimes also to provide controls (e.g. validation, rights, provenance, ratings...)

10. © Tefko Saracevic, Rutgers University9 importance standard metadata descriptions are a prerequisite to –common use –effective searching –‘intelligent’ roaming by agents –validation, ratings,

11. © Tefko Saracevic, Rutgers University10 markup languages SGML - granddaddy (standard in 1986) –marks elements within documents derived from old markups for typesetting adapted by communities producing electronic documents machine independent - reason for success –transportable from one hardware & software to another; substitutes strings many extensions & specific applications

12. © Tefko Saracevic, Rutgers University11 principles ALL markup language must specify what markup means what markup is allowed what markup is required how markup is distinguished from text all markup languages & applications follow these principles underlying concepts are fairly simple but they get very confusing real fast.

13. © Tefko Saracevic, Rutgers University12 specifications types of documents defined by DTD Document Type Definitions –many types & applications formulated vary greatly in complexity and use RDF - Resource Description Framework –a common syntax, data model & scheme for describing

14. © Tefko Saracevic, Rutgers University13 extensions HTML - most famous & successful –allows for metatags in the Head not used much, even discouraged in the body could be indirect XML - the next big thing (hopefully) data format for structured document interchange & interoperability on WWW increases functionality of SGML & combines with ease of use of HTML

15. © Tefko Saracevic, Rutgers University14 who specifies standards? formal groups –national & international standards organizations - ISO, ANSI, NISO informal groups –WWW Consortium (W3C) –Dublin Core –Library of Congress

16. © Tefko Saracevic, Rutgers University15 proliferation currently: proliferation of metadata standards activities -many domains –a lot of confusion & incompatibility –in document description & libraries coordination through liaisons & a number of projects in the U.S & internatioanly –strength: domain experts involvement –weakness: limited perspective; re-invention

17. © Tefko Saracevic, Rutgers University16 libraries in libraries metadata has a very long tradition long preceding the Web (but not called metadata) –cataloging rules, standards MARC (Machine Readable Cataloging) enabled worldwide exchange of cataloging records but long standing problems with searching

18. © Tefko Saracevic, Rutgers University17 sample of projects Encoded Archival Description (EAD) Text Encoding Initiative (TEI) Federal Geographic Data Committee ( FGDC) - geospacial data Z39.50 standards - searching crosswalks: mapping e.g. DC to MARC

19. © Tefko Saracevic, Rutgers University18 Dublin Core (DC) international initiative to describe a core set of Web resources –a set of 15 elements  Title; Creator; Subject; Description; Publisher; Contributor; Date; Type; Format; Identifier; Source; Language; Relation; Coverage; Rights wide interest & a lot of work  but not widely applied on the Web

20. © Tefko Saracevic, Rutgers University19 library interoperability library catalogs bound by proprietary software & hardware middleware needed –protocols (based on Z39.50) provide for interaction of clients with many servers (catalogs) problems remain with semantic interoperability

21. © Tefko Saracevic, Rutgers University20 digitization metadata assignment (cataloging) a key component in digitization or electronic publishing choices: a spectrum of possibilities to select & apply metadata search for automation - e.g. templates connection with cataloging, indexing

22. © Tefko Saracevic, Rutgers University21 decisions, decision –how & what to plan for metadata creation in conjunction with dl? –target audience? –scope and depth? –what to adopt? plug-in in a scheme? –how to integrate metadata projects? –needed skills? training? staffing?

23. © Tefko Saracevic, Rutgers University22 $$$$ costs of metadata: HUGE –involved operations –time, personnel, effort –learning many new things included –making decisions complex & involved cooperative activities essential libraries pushed out of libraries

24. © Tefko Saracevic, Rutgers University23