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Table Structure Understanding

by Sibling Page Comparison

Cui Tao

Data Extraction Group

Department of Computer Science

Brigham Young University

Supported by NSF

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Table Structure Understanding

Motivation Many documents contain tables Data extraction Data integration Ontology evolution

Solution Locate tables Locate table labels Locate table values Find label/value associations

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Table Structure Understanding

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Table Structure Understanding

1

2

(Gene Model, 1) = F18H3.5a

(Gene Model, 2) = F18H3.5b

:

:

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Sibling Pages

Generated output pages user query results in predefined page structure

Same web site ~ same structure

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Problems

Data rich area --- discard the irrelevant parts Find table correspondences Find mappings between table cells Find structure patterns

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HTML Table Components

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Data Rich Area

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Table Unnesting

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DOM Tree

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Simple Tree Matching

Simple Tree Matching (STM) Yang91 Maximum matching pairs of nodes O(mn)

label

Value

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Table Structure Pattern

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Table Structure Pattern

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Experimental Results

Initial Test General pattern extraction

Molecular biology: 95.6% Car ad: 100%

Dynamic adjustment Unseen structure Structure variations