| Approaches
to classification |
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| • | Earliest systems
use hard-coded wrappers |
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| – | Content-focused
(E.g., largest table cell) |
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| – | Didn’t scale |
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| • | Now, multi-class
classification using mixed features: |
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| lexical, structural and spatial. |
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| – | HTML Path
structure |
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| • | (Yang et al. 03,
Shih and Karger 04) |
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| – | Spatial random
walk using browser-exposed DOM tree |
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| • | Allows precise
layout information (Xin and Lee 04) |
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