A Survey of Unsupervised Techniques for Web Data Extraction
نویسندگان
چکیده
World Wide Web contains a large amount of data and to fetch important information from web has become a useful task. There are many web information extraction systems are developed and categorised in manual, supervised, semisupervised and unsupervised techniques. We will study unsupervised techniques and how they differ from each other. Roadrunner uses match algorithm for generating the wrapper and it does extraction at page level. ExALG uses Large and Frequently occurring equivalence class for extraction. It also does extraction at page level. FivaTech uses tree matching algorithm for generating the template. Trinity uses trinary tree which is divided into prefixes, separators and suffixes. It will be used to generate the regular expression. Trinity has a very less extraction time compared to other techniques, which makes it more efficient.
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