Panel presentation at 2nd International Workshop on Linked Web Data Management (LWDM 2012), March, 30th, 2012, Berlin, Germany

1. 1
Arbeitsgruppe
Corporate Semantic Web
Freie Universität Berlin
LWDM 2012 Workshop
LOD and Schema.org Panel
Berlin, 30. März 2012
Prof. Dr. Adrian Paschke

2. 2
Problem domains
 Syntax:
– Which representation and interchange format for
metadata? (Microformats, RDFa, Microdata)
 Semantics:
– Which metadata are allowed for Web resources
(expressiveness, metadata vocabulary, schema)
 Association problem:
– How to connect metadata with resources? (who
defines the metadata, are metadata separated
from the content, etc.)

3. 3
Requirements
Functional Requirements
– e.g., expressiveness, …
Non functional requirements at design time
– e.g., composability and extensibility, interoperability, declarative
implementability, modifiability and evolvability, reusability and
interchangeability, …
Non functional properties at runtime
– e.g., usability, understandability and explanation, correctness and
quality, scalability and efficiency, safety and information hiding (need-to-
know principle), …

4. 4
Seite 4
WHY ARE STANDARDS NECESSARY AND
USEFUL?
Standards should be based on the consolidated results of
science, technology and experience, and aimed at the
promotion of optimum community benefits.
Standard
established by
consensus
ratified by a
recognized body
provide rules, guidelines, etc.
for common and repeated use
aimed at the achievement
of some optimum

5. 5
Some Selected Challenges …
 Expressiveness and extensibility is important
– Microdata vs. RDFa
 Quality and semantics matters
– Metadata without semantics and quality maintenance is just more data
– Automted interpretation and transformation of data into meaningful information and
knowledge needs semantics (ontologies, multi-lingual context, cultural context, …)
 Without usability and pragmatics there will be no acceptance of a
standard
– Rich user-centric tool support
– Pragmatics in terms of training and incentives for additional metadata annotation needed
 The Web is a rapidly changing „eco-system“
– Updates, evolvability, robustness in unforseen situation is needed
– Stored and materialized Web of Data + Real-time data streams and event clouds