INFORMATION
RETRIEVAL
Introduction:
The
long history of information retrieval does not begin with the internet.It is
only in the last decade and a half web search engines have become pervasive and
search has become integrated into the fabric of desktop and mobile operating
systems. Prior to the broad public day-to-day use of search engines,
information retrieval systems were found in commercial and intelligence
applications as long ago as the 1960’s. The earliest computer-based searching
systems were built in the late 1940’s and were inspired by pioneering
innovation in the first half of the 20th century. As with many
computer technologies, the capabilities of retrieval systems grew with
increases in processor speed and storage capacity. The development of such
systems also reflects a rapid progression away from manual library-based approaches
of acquiring, indexing and searching information to increasingly automated
methods.
The idea of using computers to search for
relevant pieces of information was popularized in the article ‘As we may think’
by Vannevar Bush in 1945. The first automated information retrieval systems
were introduced in the 1950s and 60s. By 1970 several different techniques had
been shown to perform well on small text corpora such as the Cranfield collection
(several thousand documents). Large-scale retrieval systems such as the
Lockheed Dialog System came into use early in the 1970s. In 1992, the US
Department of Defense along with the National institute of standard and
Technology (NIST), co-sponsored the Text Retrieval Conference (TREC) as part of
the TIPSTER text program. The aim of this was to look into the information
retrieval community by supplying the infrastructure that was needed for
evaluation of text retrieval methodologies on a very large text collection.
This catalyzed research on methods that scale to huge corpora. The introduction
of web search engines has boosted the need for very large scale retrieval
systems.
Information
Retrieval Using Technology
Information
retrieval is the activity of obtaining information resources relevant for a
need from a collection of information resources. Automated information
retrieval systems are used to reduce what has been called “information overload
“. Many universities and public libraries use IR systems to provide access to
books, journals and other documents. Web search engines are the most visible IR
applications. An information retrieval process begins when a user enters a
query into the system. Queries are formal statements of information needs, for
example we use keywords to refine our search using search engines. In
information retrieval a query does not uniquely identify a single object in the
collection. Instead, several objects may match the query, perhaps with
different degrees of relevancy.
Information
storage and retrieval is the systematic process of collecting and cataloging
data so that they can be located and displayed on request. Computers and data
processing techniques have made possible the high speed, selective retrieval of
large amounts of information for government, commercial and academic purposes.
These are several basic types of information for government, commercial and
academic purposes. There are numerous types of information storage and
retrieval systems. Document retrieval systems store entire documents which are
usually retrieved by the title or by the Key words associated with the
document. In some systems the text of documents is stored as data. This permits
full text searching enabling retrieval on the basis of any words in the document.
In others, a digitalized image of the document is stored, usually on a right
once optical disc.
Database
system stores the information as a series of discrete records that are, in turn
divided into discrete fields. For example, name, address and phone number are
the basic personal information that we can store about a person. Records can be
searched and retrieved on the basis of the content of the fields (e.g. all
people who have a particular telephone area code). The data are stored within
the computer, either in main storage or in auxiliary storage, for ready access.
Reference retrieval systems store references to documents rather than the
documents themselves. Such systems, in response to a search request, provide
the titles of relevant documents and frequently their physical locations. Such
systems are efficient when large amounts of different types of printed data
must be stored. They have proven extremely effective in libraries where material
is constantly changing.
In
the recovery of information in the database stored in a computer, we usually
take two approaches. First approach uses the database index i.e. the keyword
searching and the second approach is by traversing the database using hypertext
or hyper media links. Keyword searching has been the dominant approach to text
retrieval since the early 1960s; hypertext has so far been confined largely to
personal or corporate information retrieval applications. Evolving information
retrieval techniques, exemplified by developments with modern internet search
engines combine natural language, hyperlinks and keyword searching. Other
techniques that seek higher levels of retrieval precision are studied by
researchers involved with artificial intelligence.
For effectively
retrieving relevant documents by IR strategies, the documents are typically
transformed into a suitable representation. Each retrieval strategy
incorporates a specific model for its document representation purposes. The
conventional approach to manage large collections of information originates
from the discipline of librarianship. Commonly items such as books or papers
were indexed using cataloguing schemes.
The
1960s saw a wide range of activities reflecting the move from simply asking if
IR was possible on computers to determining means of improving IR systems. By
the 1990s there arouse a vast increase in the number of websites and quantity
of pages. World Wide Web was established by late 1990. Year by year the number
of websites were multiplying and thus information was revolutionized by
technology.
Retrieving
Information-A Study Skill
In
our classroom situation, retrieving skills will mean summarizing, classifying,
indexing and getting back the stored information. The conventional précis writing
will help us to make summaries and outlines. In précis writing, we condense the
original message into a minimum number of words. Summaries can be made with the
help of notes taken.
There
are certain effective methods of notes taking and summarizing. First, one has
to read the given material carefully and understand the content. Then you may
underline or highlight the important (message carrying) words and sentences in
the passage. With these words we can create effective notes. With the brief and
important words or sentences in the note, write a brief summary. One should
take utmost care in that the content of the given material is not altered or
changed. We are just to modify it by making it precise. Careful reading of the
passage helps to summarize the content. But still one third of the original
material should be kept aloof. If necessary, we can remove a few more unwanted
words or sentences from the summary.
A
good summary must have the following qualities in it:
1. It
is brief and clear.
2. The
main ideas of the passage are presented in it.
3. Unnecessary
avoidable details are not present in it.
4. It
is simple and easy to understand.
The
learner must be taught a classifying and indexing scheme so that the collected information
is stored in some systematic manner. The use of aperture cards or some other
methods that will facilitate the retrieval of the required information or the
document or a book or an abstract is to be taught. Once the learner gets the
bits of information, it is stored in some systematic manner. Once we get a bit
of information, we need to know how to put them together or expanda given
summary. This involves the convention expansion and paraphrasing. In a
paraphrase or expansion, we try to express the meaning of the original message
clearly and more fully. In teaching retrieving skills, we need to make use of
the techniques used in documentation that are to be taught. The best place for
such training is the information center or the library.
Using
a Library:
Library
is known as the treasure house of information. The students need to know how to
use a library, for which they should understand the basis of classification.
Students should also be taught to use the library catalogue and how to borrow a
book. They need to know how to locate a book, articles, by giving the title or
the authors of a book or journal. The students should be taught to conduct the
‘information hunt’ effectively by gathering maximum useful information within a
limited period of time. At the same time, they should be trained to be
up-to-date with the technological advancements. Therefore, the teacher should
give assistance to the students in using internet for collection of
information.
Books:
In
using books, they should be familiar with the contents, index, appendix and
bibliography. The students should know how to write bibliographical information,how
to write quotations etc. They must be taught how to use an index, the content page,
appendices, footnotes etc. These reference skills will be useful in the long
run.
Referring
to periodical:
Periodicals,
commonly known as journals and magazines are another excellent source of
information. Thisinformationis current and fresh. Periodicals cover a vast area
of knowledge which may be important or unimportant. They provide different viewpoints
about the same topic, whereas books are elaborations of one view point. Thus periodicals
are as important as books as a source of information.
Referring
to Abstracts:
Abstract of articles
published in the periodicals is also available for researchers through
abstracting services. They provide the findings or conclusions of the authors
and the user can choose the abstract if it is suitable to his purpose.
Abstracts are published periodically in every discipline .They are arranged
subject wise. The most popular abstracting services are;
1.ERIC: Resources in Educations and Current
India to Journals in Education.
2. Psychological Abstracts.
3. Language and literature abstracts.
Besides
the above skills, the learner has to learn and know how to prepare for his or
her examination. The skills in retrieving information calls for a condensation
and from this condensed date, they are able to produce or in a way re-produce
those information or answers that are needed in an examination.
Technological
advancements made the explosion of information. From the 1990s computers,
mobile phones and any other means of information technology have become
inevitable for a normal human being. Now we have tons of information at our
finger tips. We are supposed to use it according to its relevance and our needs
so as to gather specific and in-depth knowledge about what we are unaware.
Conclusion:
The
20th and early 21st centuries were transformational in
the way people accessed information. In 1912, a person with an information need
would probably go to local library and using a catalogue, locate books or
documents that hopefully answered that need. But the scope of available
information would be limited the size of their library. Now, because of the
ubiquity of web-based search, with an internet connection, one can
instantaneously access hundreds of terabytes of web pages, video clips, news,
images, social media, scanned books, academic papers, music, televisions,
programs and films. In the last few years, access has been also possible from a
mobile phone. Thus information is available anywhere any time, we should make use
of it in a positive way so as to bring a change in our own attitude and in the
society.
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