- Free Articles
-
Time in Philosophical Logic
Encyclopedia of Database Systems
-
Geographic Information Systems
Encyclopedia of Database Systems
-
Indoor Localization
Encyclopedia of GIS
-
Suffix Tree Construction in Hierarchical Memory
Encyclopedia of Algorithms
-
Probabilistic Data Forwarding in Wireless Sensor Networks
Encyclopedia of Algorithms
- More Free Articles
This is the free portion of the full article.
The full article
is available to licensed users only.
How do I get access?
Data Integration in Web Data Extraction System
Synonyms
Definition
Data integration in Web data extraction systems refers to the task of providing a uniform access to multiple Web data sources. The ultimate goal of Web data integration is similar to the objective of data integration in database systems. However, the main difference is that Web data sources (i.e., Websites) do not feature a structured data format which can be accessed and queried by means of a query language. In contrast, Web data extraction systems need to provide an additional layer to transform Web pages into (semi)-structured data sources. Typically, this layer provides an extraction mechanism that exploits the inherent document structure of HTML pages (i.e., the document object model), the content of the document (i.e., text), visual cues (i.e., formatting and layout), and the inter document structure (i.e., hyperlinks) to