DAML Homework Assignment 1 "Quick Look"

This page presents an initial look at the DAML ontologies and content pages developed by DAML program participants for DAML Homework Assignment 1.

A summary of all pages is available here. All submitted ontologies have been added to the DAML Ontology Library.

Statistics

45 content roots were submitted.

About 10,000 DAML statements were submitted.

Use of Language Features

• daml-ont:List
  • SRI *.daml
  • Teknowledge Palo Alto Ontology.daml
  • BAH personal-info.daml
• multiple inheritance
  • CMU atlas-employment_categories.daml#Research
• subPropertyOf
  • Teknowledge LA ResearchProjectOntology.daml
  • DRC *.daml
• daml:restrictedBy
  • Stanford DB swrc-onto-2000-09-10.daml
  • CMU atlas-date.daml
  • SRI *.daml
• Literal typing
  • CMU atlas-date.daml uses http://www.daml.org/2000/10/daml-num.daml#Integer
  • BBN projects-20000911.daml uses http://www.w3.org/TR/1999/PR-rdf-schema-19990303#Literal [old URI for RDFS, currently RDF API]
  • SRI *.daml uses http://www.w3.org/2000/01/rdf-schema#Literal
  • BAH personal-info.daml and Stanford DB swrc-onto-2000-09-10.daml uses http://www.w3.org/TR/xmlschema-2/#string [new URI for RDFS]
  • Stanford KSL ksl-daml-desc.daml defines and uses Classes #STRING and #INTEGER [Doesn't this imply that these are Resources rather than Literals?]
  • UMBC talk-ont.daml defines and uses Classes #String and #Integer [Doesn't this imply that these are Resources rather than Literals?]
• equivalentTo
  • UMBC talk-ont.daml
  • LM M&DS ubot-ont.daml
  • SRI *.daml
  • Teknowledge Palo Alto Ontology.daml
• oneOf
  • DRC *.daml
  • Teknowledge LA ResearchProjectOntology.daml
  • CMU *.daml
• reification
  • ?

Key Mechanisms Used

Examples of naming are available in the DAML Project Directory.

Lessons Learned

• lists: BAH, SRI, Stanford KSL, Teknowledge Palo Alto
• UML: GRCI, LM M&DS
• naming: Stanford DB, BBN, UMBC
• placement: UMBC, BBN, ...
• documentation/examples:

Emerging Best Practices

• Adopt RDF capitalization conventions:
  • use full words
  • capitalize first letter for classes, lowercase first letter for properties
  • capitalize first letter of each subsequent word
  • no _'s or other punctuation.
  • Most folks did this.
• Separate Class/Property definitions from instances.
  • Almost everyone did this.
  • Teknowledge Palo Alto Ontology.daml defines SoftwareDevelopmentBusiness, BusinessUnit, and Person instances as part of their ontology.
• Probably want some naming convention to distinguish DAML files containing DAML ontologies from those containing content
  • BBN projects-20000911.daml
  • ISI *.o.daml, *.d.daml
  • DRC *-ont.daml
• Use subProperties rather than properties on intermediate objects to distinguish roles, etc.
  • Teknowledge LA ResearchProjectOntology.daml#isPrincipalInvestigator subproperty of #inProject.
• Use ID to name instances.
• Use domain/range constraints and/or restrictedBy for Properties.

Problems

• homework/assignment.html has bad syntax for associating an Action instance with an ActionItem (what was I thinking?). SRI *-homepage.daml may have copied this in associating researcher:department, org:name, and contactinfo with Researchers
• BAH personal-info.daml uses cardinality and maxCardinality as attributes of rdfs:Property
• CMU atlas-cmu.daml uses disjoin within Organization; presumably this should be disjointUnionOf. Note: daml-ex.daml uses disjointFrom, which is not defined in daml-ont.daml.
• GRCI ProjectOntology.daml uses 'String' and 'Integer' as Property range's
• Teknowledge LA ResearchProjectOntology.daml uses subproperty rather than subPropertyOf
• UMBC talk-ont.daml originally had Property definitions within Class definitions, and was not parsable by RDF API
• UMBC classification.daml uses daml:ID which results in genidNNN Classes from RDF API
• CMU content pages use a hybrid abbreviated syntax

    <atlas:property="value">
  

  that isn't well-formed XML

Other Issues

• Some Researchers in SRI *-homepage.daml don't have IDs, making them hard to reference later.
• No general means to embed RDF in HTML for IE 5?
• Teknowledge LA uses ResearchProjectOntology.daml/Class rather than uri#Class
• absolute vs. relative URIs
  • several projects (BBN, ISI) used relative URIs to refer to their ontologies
  • RDF API doesn't make relative URIs absolute -- a higher level needs to do that
  • the use of non-standard URI protocols (or was ":" just intended as a separator?) in Stanford DB URIs such as person:sde complicates converting relative URIs to absolute URIs (java.net.URI interprets "person:" prefix as an unknown protocol)

Kudos

• GRCI demonstrated how to use the same content for both DAML statements and HTML rendering, eliminating duplication and potential inconsistencies.
• BAH generated their content dynamically using Java Servlets
• LM M&DS reused the SHOE ontologies, manually converting portions of them to DAML