The document discusses the construction of a model for querying capabilities of deep web sources, which are significantly larger than the surface web. It defines various attributes related to form submissions and classifies valid and invalid queries, focusing on atomic queries as the smallest valid query units. The paper also outlines a search algorithm, experiments on multiple datasets, and highlights future work involving value type identification.

1. CS-690 Fall-2009 Querying Capability Modelling and Construction of Deep Web Sources Paper by: Liangcai Shu, Weiyi Meng, Hai Fe, and Clement Yu Presentation by: Fabian Alenius

2. Problem definition Deep Web is the information hidden behind HTML forms

3. Information in Deep Web is 400-550 times larger than the surface web

4. Crawlers need to extract

5. information

6. Problem definition Task: Build a model of query interfaces of Deep Web sources, i.e. what types of form submissions are accepted

7. A form submission consists of a set of values, one for every field of the form

8. Querying Capability Querying capability specifies what queries are valid

9. An attribute is a field in a form

10. A query is a set of attributes

11. A set query instances are a set of attribute and value pairs, e.g. {<Author, Tolkien>, <Title, Bilbo>}

12. Four types of attributes Functional Attribute Range Attribute Categorical Attribute Value-Infinite Attribute

13. Conditional Dependency Given Attribute A and Condition C

14. Conditional dependency – value of C insignificant if A is null

15. A -> C

16. Attribute Unions Attribute A , Value type T, and Constraints C together form union AU(A, T, C 1 , ..., C n )

17. T is not attribute type, but value type (e.g. phone, zip code, etc.)

18. Valid queries – accepted; Invalid queries – rejected