Tuesday, 26 August 2014

How Data Scraping can extract Data from a Complex Web Page?

The Web is a huge repository where data resides both in structured as well as unstructured formats and presents its own set of challenges in the extraction.The complexity of a website is defined by the way it displays its data. Most of the structured data available on the web are sourced from an underlying database, while the unstructured data are randomly available. Both, however, make querying for data a complicated process. Moreover, Websites display the information in HTML format marked by their unique structure and layout, thereby complicating the process of data extraction even further. There are, however, certain ways in which appropriate data can be extracted from these complex web sources.
Complete Automation of Data Extraction process

There are several standard automation tools which require human inputs in order to start the extraction process. These Web automation processes, known as the Wrappers, need to be configured by a human administrator so as to carry out the extraction process in a pre-designated manner. This method, therefore, is also referred to as extraction through the supervised approach. Owing to the use of human intelligence in pre-defining the extraction process, this method assures a higher rate of accuracy. However, it is not without its fair share of limitations. Some of these are:
  •  It fails to scale-upsufficiently in order to take on a higher volume of extraction more frequently and from multiple sites. 
  •  They fail to automatically integrate and normalize data from a large number of websites owing to its inherent workflow issues 
As a result, therefore, fully automated data extraction tools which do not require any human input are a better option to tackle complex web pages. The benefits they afford include the following:

  • They are better equipped to scale up as and when needed 
  •  They can handle complex and dynamic sites, including those running on Java and AJAX 
  •  They are definitely more efficient than the use of manual processes, running scripts or even using Web Scrapers.

Selective Extraction

Web sites today comprise a host of unwanted content elements that are not required for your business purpose. Manual processes, however are unable to eliminate these redundant features from being included. Data Extraction tools can be geared to exclude these in the extraction process. The following things are noted in order to ensure that:
  • As most irrelevant content elements like banners, advertisements and the like are found at the beginning or the end of the web page, the tool can be configured so as to ignore the specific regions during the extraction process. 
  • In certain web pages, elements like navigation links are often found in the first or last records of the data region. The tool can be tuned to identify these and remove them during extraction. 
  • Tools are equipped to match similarity patterns within data records and remove ones that bear low similarity with essential data elements as these are likely to have unwanted information.

Web Data Extraction through automated processes provides the precision and efficiency required to extract data from complex web pages. If engaged the process helps you to achieve satisfactory innovations in your business processes.

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