The Pragmatic Web: Preliminary Thoughts

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The Pragmatic WebPreliminary Thoughts

• Munindar P. Singh
• www.csc.ncsu.edu/faculty/mpsingh
• singh_at_ncsu.edu
• April 2002

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Conclusions

• When the Semantic Web comes around, it will come
  in the form of the Pragmatic Web.
• Need to develop new abstractions, not simply
  rehash old work.
• Must consider (besides data)
• Process.
• Interaction.
• Context.

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Semiotics

• Syntax structure.
• Semantics meaning as captured in syntax.
• Function from structures to meaning objects.
• Compositional semantics above function is a
  homomorphism.
• Pragmatics meaning in usage.
• Context.
• Indexicals, e.g., I, here, now.
• Deixis, e.g., this, that.

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Semantic Web

• Mission enable information to be shared by
  applications across the web.
• Methodology Develop standardized representations
  for markup.

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Does the methodology serve the mission?

• Why will standardizing the ontology
  representations solve the problem?
• Though valuable, ontologies didnt solve the
  problem of sharing information sharing in
  databases.
• Standardizing representations for them will
  simplify exchange of metadata, but not of its
  usage.

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Challenges for the Semantic Web

• Technical
• Limits of semantics designing generic
  representations independent of usage.
• Engineering Easy to build demos difficult to
  build real systems.
• Technical culture emphasis on visions that are
• Glitzy mobile or pervasive devices talking to
  each other to enact fancy demos, conceptually
  glued together for a demo
• Weak on identification of anything new, except
  that they execute over the Web or with new
  devices.

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Service Composition

• Essential to personalize services.
• The value is in the context.
• No need for intermediaries otherwise, e.g.,
  airlines versus travel agents.

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Abstractions for Openness

• All science is either physics or stamp collecting
  Ernest Rutherford.
• Old physics
• Describe process of composition procedurally in a
  trivial execution model (a graph).
• All subtlety pushed to the data connectors.
• So what is the new physics?

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Describing Services and Desired Compositions

• Properties of services (inadequacy of WSDL)
• Autonomy.
• Heterogeneity.
• Long-lived, evolving.
• Cooperativeness.
• Specifying compositions.
• Testing compliance.

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Discovering Services

• Inadequacy of UDDI.
• Trust.
• Dependent on usage context.
• Often without trusted third parties.
• Evaluation.
• Reputation.

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Describing Compositions

• Inadequacy of WSDL in supporting compositions.
• Inadequacy of WSFL, DAML-S for specifying
  compositions (they have other features and they
  are improving, but still).
• Rehash of workflow procedural primitives (split,
  join, etc.)

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Principles

• User before provider. Consumers are presented as
  composers of services with idiosyncratic needs
  and context dependent requirements.
• Interaction before representation. Services
  should describe the interactions and minimize the
  representational dependencies.
• Process before data. Processes behind the data
  give a better clue to its meaning than a
  process-independent (impossible) semantics.
• Central position to process and context, not to
  data.

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Are we arguing against the Semantic Web? No

• If man evolved from monkeys and apes, why do we
  still have monkeys and apes? George Carlin
• Work on pragmatics will promote the semantics,
  just as the semantics promotes the syntax.
• The pragmatics endeavor is a special direction
  within the semantics endeavor.

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Plugs

• IEEE Internet Computing
• Theme issues.
• Always welcomes solid articles on Semantic Web
  and Web Services.
• Workshop on trust, deception, fraud, privacy,
  2002.
• Workshop on regulated agent-based social systems,
  2002.