1. Data Extraction From HTML Tables Cui Tao Department of Computer Science Brigham Young University

2. Information In Tables  Nowadays, significant portion of the information on the Wed is stored in tables.

3. The Ontology-Based Extraction

5. Major Problems  In the tables, the values and their corresponding attributes are separately. But the ontology can only extract the data when they are together.  Sometimes the attributes in the table are the values in the database, the values in the table are only the identifier of the attributes.  Sometimes, the values in one cell of the table may informs several attribute values in the database.

6. Attribute-Value Pair Attribute: (part of the) constant/key word rule

7. How To Solve This Problem? Put the attribute-value pair together. Try both order.

8. More General…

9.  The attributes in the table are actually values in the database… Attribute Value

10. How To Solve This Problem?  Put attribute in the file depends on the Boolean value

11. Value Multiple Information

12. More Problems …