1 Metadata –Information about information – Different objects, different forms – e.g. Library catalogue record Property:Value: Author Ian Beardwell Publisher Pitman Date published 1994 Subject classification Human Resource Management ISBNISBN

2 Why is it important? –Describe and locate information –Judge relevance of information –Promote good information management Plus.... –Search tools and information gateways beginning to use metadata when locating and describing resources

3 HTML 'META' Tag References W3C HTML 4.0 Recommendation html40/struct/global.html#edef-META Web Design Group head/meta.html

4 Interpreting Attributes Similar attributes may be interpreted differently eg. DATE -what does it mean? –the date the resource was put on the web? –the date the original paper copy was written? Consistency of values is important: –it ensures searching for information is effective –it allows standard searches to be made

5 Setting Parameters Inconsistencies can be reduced: –Clear labelling of attributes lastname, initials, title –Formats and rules formats - Author = Beardwell, I, Dr Date = 01-Jan-97 cataloguing rules - guidance on interpreting labels

6 Dublin Core (DC) Workshop held in Dublin, Ohio – 'Document-Like Objects' HTML, Postscript, images 15 core elements: Title, Creator, Subject, Description, Publisher, Contributors, Date, Type, Format, Identifier, Source, Language, Relation, Coverage and Rights Flexibility provided by qualifiers: – Type: distinguishes different uses of an element – Scheme: identifies recognised coding system Link tag points to definition of DC element

7 DC Example

8 Metadata Development Which format to use? – Dublin Core? New standards? Format can be easily altered by generators – DC DOT Separate the metadata from the information Resource Description Framework (RDF)

9 RDF Resource Description Framework –aims to provide the infrastructure to exchange metadata on the web –allows integration of different metadata schemes –enables automated processing of web resources –interoperability between applications that exchange machine- understandable information Syntax uses XML

10 Example World Wide Web Consortium W3C Home Page T02:27 Remote definition of the RDF statements and the XML namespace 's:' Identify the resource to be described Metadata Common group name (namespace)

11 Uses of RDF Resource discovery - search engines Cataloguing - describe content and content relationships Describing intellectual property rights Intelligent software agents - info sharing Content rating Privacy preferences/policies Collections of pages as a single "document" "RDF with digital signatures will be key to building the 'Web of Trust' for electronic commerce, collaboration, and other applications. "

12 Disadvantages of Metadata –In the short-term, metadata imposes a load on the server –Metadata stored in separate files? –Difficult to convince information providers of its importance –Need for standardised usage and procedures –Not trusted by some search engines - 'keyword spamming'

13 Future… –Metadata is becoming very important –Metadata may need to be added retrospectively to thousands of documents –Start collecting data now! –Automate as much as possible –Ensure information providers use metadata

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