Wednesday,Jun 18 2008, 02:07:20 AMKnoelwsys Web Data Extraction

Web Data Extraction

The unabated growth of the Web has resulted in a situation in which more information is available to more people than ever in human history. Along with this unprecedented growth has come the inevitable problem of information overload. To counteract this information overload, users typically rely on search engines (like Google and AllTheWeb) or on manually-created categorization hierarchies (like Yahoo! and the Open Directory Project). Though excellent for accessing Web pages on the so-called "crawlable" web, these approaches overlook a much more massive and high-quality resource: the Deep Web. 1. Data Collection 2. Data Extraction

The Deep Web (or Hidden Web) comprises all information that resides in autonomous databases behind portals and information providers' web front-ends. Web pages in the Deep Web are dynamically-generated in response to a query through a web site's search form and often contain rich content. A recent study has estimated the size of the Deep Web to be more than 500 billion pages, whereas the size of the "crawlable" web is only 1% of the Deep Web (i.e., less than 5 billion pages).3. Data Extraction from Web
4. Extracteur Web Even those web sites with some static links that are "crawlable" by a search engine often have much more information available only through a query interface. Unlocking this vast deep web content presents a major research challenge.

In analogy to search engines over the "crawlable" web, we argue that one way to unlock the Deep Web is to employ a fully automated approach to extracting, indexing, and searching the query-related information-rich regions from dynamic web pages. For this miniproject, we focus on the first of these: extracting data from the Deep Web.

Extracting the interesting information from a Deep Web site requires many things: including scalable and robust methods for analyzing dynamic web pages of a given web site, discovering and locating the query-related information-rich content regions, and extracting itemized objects within each region.5. Extraction,Extraction and Extraction on web! 6. Extraction Information Information By full automation, we mean that the extraction algorithms should be designed independently of the presentation features or specific content of the web pages, such as the specific ways in which the query-related information is laid out or the specific locations where the navigational links and advertisement information are placed in the web pages.

There are many possible 7001-miniprojects. Feel free to talk to either of us for more details. Here are a few possibilities to consider:

1. Develop a Web-based demo for clustering pages of a similar type from a single Deep Web source. 21. Web Grabber
22. Web Mining For example, AllMusic produces three types of pages in response to a user query: a direct match page (e.g. for Elvis Presley), a list of links to match pages (e.g. a list of all artists named Jackson), and a page with no matches. 7. Html Data Extraction 8. Html Extraction As a first-step to extracting the relevant data from each page, you may develop techniques to separate out the pages that contain query matches from pages that contain no matches, and perhaps, rank each group based on some metric of quality.

2. Design a system for extracting interesting data from a collection of pages from a Deep Web source. You might define a set of regular expression that can identify dates, prices, or names.9. Information Extraction 10. News Content for Web Site Develop a small program that converts a page into a type structure. For example, given a DOM model of a web page, identify all of the types that you have defined, and replace the string tokens with XML tags identifying the types.11. Screen Scraping Replace all non-type tokens with a generic type, and return the tree as a full type structure). Alternatively, you may suggest your own approach for extracting data.

3. Develop a system to recognize names in page. 12. Site Scraping Given a list of names and a web page, identify possible matches in the page. Based on the structure of the page and the distribution of recognized names, identify strings that may also be names based on their location in the DOM tree heirarchy representing the page.

4. Write a survey paper about current approaches for 13. Web Data Extraction 14. Web Data Extraction understanding and analyzing the Deep Web. Be sure to include many of your own comments on the viability of the approaches you review.

5. Or, feel free to suggest a miniproject of your own.

Extracting information from semistructured Web documents is an important task for many information agents. 15. Web Data Extraction Service 16. Web Data Extraction Services Over the past few years, researchers have developed an extensive family of generic information extraction techniques based on supervised approaches that learn extraction rules from user-labeled training examples.

However, annotating training data can be expensive when thousands of data sources must be wrapped. 17. Web Data Extractor
18. Web Data Grabber Web Data Miner, a semisupervised IE system, produces extraction rules without detailed annotation of the training documents. Instead, it gives a rough segment that contains all that need to be extracted in one record as an example.

Web Data Miner is designed with visualization support such that it 19. Web Data Mining 20. Web Extraction displays the discovered records in a spreadsheet-like table for schema assignment. 23. Web Scraping 24. Website Extraction Experiments show that Web Data Miner performs well for program-generated Web pages with very few training pages and little user intervention.

Index Terms-25. Website Scraping semistructured data, Web data extraction, multiple string alignment, rule generalization

Build a website, Direct Search Engine 1, Direct Search Engine 2, Web Data , Web Content, Web Data Extraction

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