Two-Level Semantic Annotation Model BYU Spring Conference 2007 Yihong Ding Sponsored by NSF

2 Semantic Web Content is represented in explicit, shared, conceptualizations. Consequence Machines can understand meaning Machines can derive implicit logics Ontology

3 Semantic Annotation: Enable the Semantic Web Metadata links data in a web page to defined concepts in an ontology Annotated data becomes machine- processable

4 Sample Annotation FORD

5 Two Contradictive Annotation Methods Pure ontology-based annotation Layout-driven annotation

6 Ontology-based Annotation Using defined data-recognition patterns in ontologies to directly annotate web content Examples in extraction ontologies External Representation Price: \d+|\d?\d?\d.\d\d Contextual Representation Context phrases (left, right), e.g. \$? Context keywords: e.g. price | obo | neg(\.|otiable)

7 Ontology-based Annotation Pros Resilient to varying domains and page layouts No mapping requirements between recognition patterns and ontology definitions Cons Accuracy depends on how good the knowledge base is Creation of recognition patterns Execution speed

8 Layout-Driven Annotation Using defined page layout patterns to annotate web content Example (screen-scraper) You've Got Mail <!-- document.write(' larger image '); //--> larger image Model: DVD-YGEM $34.99 Shipping Weight: 7.00 lbs. 10 Units in Stock Manufactured by: Warner Quantity

9 Layout-Driven Annotation Pros More accurate Faster No knowledge base required Cons Layout-pattern generation Layout-pattern regeneration Layout-pattern maintenance Mappings between layout-patterns and ontology definitions

10 Observation These two annotation methods are complementary.

11 Two-Layer Annotation Model Conceptual Annotator using ontology-based IE wrapper Document Structural Annotator Sample Annotation Process Same-Layout Documents Massive Annotation Process

12 Data-recognition Pattern (Price) Price: \$?\d+|\d?\d?\d.\d\d You've Got Mail <!-- document.write(' larger image '); //--> larger image Model: DVD-YGEM $34.99 Shipping Weight: 7.00 lbs. 10 Units in Stock Manufactured by: Warner Quantity

13 Two-Layer Annotation Model, What do we gain? All the benefits of the two annotation methods Resilient Mapping problem eliminated Knowledge-base problems mitigated Maintenance problem mitigated More accurate Faster Even more Automatic augmentation of knowledge base Key to large-scale annotation for the web

14 Conclusion Contradictory is a synonym of complementary Two-level annotation model solves a traditional problem on semantic annotation and it is a key to large-scale annotation for the web