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Information Retreival System: Implementation





NCBI provides an information retrieval system, Entrez, designed to provide user friendly access to biomedical data including structural, molecular, sequences and literature.  Entrez provides access and searching facilities to more than 30 databases of genome, health, structural, literature, sequence and chemical. It provides faecet, limited and advance searching option with Boolean operators to customize user’s query. It also facilitates querying with wild card characters, mapping and controlled vocabulary. Web implementation of Entrez has more valuable applications and benefits over Network Entrez as it facilitates searching with a tremendous amount of data in different databases. Entrez provides navigational links between different databases either provided by NCBI or external (journal/databases) for each record by using two types of relationships: neighbors and hard links. Both of these types of relationships have been found on the basis of controlled vocabulary and algorithms working behind Entrez.








Implementation






Irrespective of platform, NCBI retrieval system Entrez searches are executed with the help of one of two interfaces.



  • Network Entrez: This interface comprises of a client-server implementation. It is fastest and makes a direct association to NCBI ‘‘dispatcher.’’ Its user friendly graphical interface provides a series of different windows and every time whenever new information is demanded, a different window seems on user’s screen. For the reason that the client software exist in user’s machine, it depends on user to get, install, and continue the software, downloading updates as new properties are announced. It also comes with interactive and/or graphical viewers for three-dimensional structures and genome sequences.

    Most widely used application of Entrez is through World Wide Web (WWW). This choice use variety of existing Web browsers, such as Netscape, Internet Explorer, and Google Chrome to provide searching results to the user’s desktop. In an entry, Web offers hard links and neighboring associations defined, can be easily presented as hypertext, permitting to navigate through clicking on particular words.

    Using Web implementation of Entrez provides advantage over the Network version as it permits navigation to external data sources either a part of Entrez or part of external databases/journals. Another aspect is internet speed over Network version and in the presentation. Web Entrez provides results in the form of pagination whereas Network version provides a series of input and output windows for presentation. Both implementation method produces same results, however, Web Entrez can navigate user to external journals and databases.











 
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