Information Storage and Retrieval Systems

1) What are the objectives which should be kept in mind while designing an ISAR?
A system designer should keep in mind following points while designing an ISAR:

  • The ISAR should act as facilitator between the information (contained in document) and the users
  • Search results must be free from any kind of ambiguity 
  • Searching through the system should take minimum time
  • ISAR should have user friendly interface.

2) Name different types of ISAR systems.
There are different kinds of ISAR systems such as:

  • Database Management System (DBMS)
  • Text Retrieval System
  • Management Information System (MIS)
  • Decision Support System
  • Knowledge Based System.

3) What are the different components of ISAR system?
An ISAR system has following components:

  • User Interface
  • Knowledge Base
  • Search Agent.

Boolean Query : A query that is a Boolean combination of terms. For example, Information AND
Retrieval, Vision OR Sight.
Classification : The process of deciding the appropriate category for a given document.
Collection : A group of documents that a user wishes to get information from.
Information Retrieval : The study of systems for indexing, searching, and recalling data, particularly text or other unstructured forms.
Inverted File : A representation for a collection that is essentially an index.
Precision : A standard measure of IR performance, precision is defined as the number of relevant
documents retrieved divided by the total number of documents retrieved.
Query : A string of words that characterizes the information that the user seeks.
Recall : A standard measure of IR performance, recall is defined as the number of relevant documents
retrieved divided by the total number of relevant documents in the collection.
Relevance : An abstract measure of how well a document satisfies the user’s information need. Ideally, system should retrieve all of the relevant documents.
Robot : Any browser program which follows hypertext links and accesses web pages but is not directly under human control. Examples are the search engine spiders, the ‘harvesting’ programs which extract e-mail addresses and other data from web pages and various intelligent web searching
Spider : Also called a robot, a program that scans the web looking for URLs. It is started at a
particular web page, and then access all the links from it. In this manner, it traverses the graph formed by the WWW. It can record information about those servers for the creation of an index or search facility. Most search engines are created using spiders. The problem with them is, if not written properly, they can make a large number of hits on a server in a short space of time, causing the system’s performance to decay.
URL (Uniform Resource : A URL (Uniform Resource Locator) is the Locator) address of a file (resource) accessible on the Internet, e.g.,