Archive for the ‘Extraction’ Category

Web Data Extraction, Applications and Techniques: A Survey

Tuesday, September 11th, 2012

Web Data Extraction, Applications and Techniques: A Survey by Emilio Ferrara, Pasquale De Meo, Giacomo Fiumara, Robert Baumgartner.

Abstract:

Web Data Extraction is an important problem that has been studied by means of different scientific tools and in a broad range of application domains. Many approaches to extracting data from the Web have been designed to solve specific problems and operate in ad-hoc application domains. Other approaches, instead, heavily reuse techniques and algorithms developed in the field of Information Extraction.

This survey aims at providing a structured and comprehensive overview of the research efforts made in the field of Web Data Extraction. The fil rouge of our work is to provide a classification of existing approaches in terms of the applications for which they have been employed. This differentiates our work from other surveys devoted to classify existing approaches on the basis of the algorithms, techniques and tools they use.

We classified Web Data Extraction approaches into categories and, for each category, we illustrated the basic techniques along with their main variants.

We grouped existing applications in two main areas: applications at the Enterprise level and at the Social Web level. Such a classification relies on a twofold reason: on one hand, Web Data Extraction techniques emerged as a key tool to perform data analysis in Business and Competitive Intelligence systems as well as for business process re-engineering. On the other hand, Web Data Extraction techniques allow for gathering a large amount of structured data continuously generated and disseminated by Web 2.0, Social Media and Online Social Network users and this offers unprecedented opportunities of analyzing human behaviors on a large scale.

We discussed also about the potential of cross-fertilization, i.e., on the possibility of re-using Web Data Extraction techniques originally designed to work in a given domain, in other domains.

Comprehensive (> 50 pages) survey of web data extraction. Supplements and updates existing work by its focus on classifying by field of use, web data extraction.

Very likely to lead to adaptation of techniques from one field to another.

Parsing Wikipedia Articles: Wikipedia Extractor and Cloud9

Monday, November 28th, 2011

Parsing Wikipedia Articles: Wikipedia Extractor and Cloud9 by Ryan Rosario.

From the post:

Lately I have doing a lot of work with the Wikipedia XML dump as a corpus. Wikipedia provides a wealth information to researchers in easy to access formats including XML, SQL and HTML dumps for all language properties. Some of the data freely available from the Wikimedia Foundation include

  • article content and template pages
  • article content with revision history (huge files)
  • article content including user pages and talk pages
  • redirect graph
  • page-to-page link lists: redirects, categories, image links, page links, interwiki etc.
  • image metadata
  • site statistics

The above resources are available not only for Wikipedia, but for other Wikimedia Foundation projects such as Wiktionary, Wikibooks and Wikiquotes.

All of that is available but also lacking any consistent usage of syntax. Ryan stumbles upon Wikipedia Extractor, which has pluses and minuses, an example of that latter being really slow. Things look up for Ryan when he is reminded about Cloud9, which is designed for a MapReduce environment.

Read the post to see how things turned out for Ryan using Cloud9.

Depending on your needs, Wikipedia URLs are a start on subject identifiers, although you will probably need to create some for your particular domain.

Sofia-ML and Maui: Two Cool Machine Learning and Extraction libraries – Post

Friday, January 28th, 2011

Sofia-ML and Maui: Two Cool Machine Learning and Extraction libraries

Jeff Dalton reports on two software packages for text analysis.

These are examples of just some of the tools that could be run on a corpus like the Afghan War Diaries.