1) What is the difference between a high recall and a high precision search?
A high recall search aims to produce the maximum number of relevant items from a collection (even if in that process some non-relevant items are retrieved) while a high precision search aims to produce precisely the relevant items (the objective being to retrieve as many relevant items as possible, and at the same time filtering out non-relevant items).
2) What is a pre-search interview in the context of online information retrieval?
A pre-search interview is a conversation that takes place between a user and member of the information staff regarding the actual information requirements of the user.
3) How does a truncated search improve the results of a search?
A truncation search retrieves all those records where part of the search term occurs. For example a truncation search with ‘librar$’ will retrieve records with terms like libraries, library, librarian, etc. Thus, a truncation search produces more search results.
4) Which of the two search expressions will produce more hits (search results) and why?
a) Classification and indexing
b) Classification or indexing
The second search, i.e., ‘classification or indexing’ will produce more results since this search will retrieve all those records where either or both the search terms occur, whereas the first search expression ‘classification and indexing’ will retrieve only those items where both the search terms occur.
5) What is the difference between a Boolean search and a proximity search?
A proximity search is as good as a Boolean and search in the sense that it searches for the occurrence of two or more search terms in the documents. However, it adds more constraints by specifying the distance between the search terms, and therefore the search output becomes more specific.
6) What is the difference between a keyword search and a subject search?
A keyword search allows users to enter one or more keywords pertaining to their query. The search keywords can appear anywhere, or in one or more chosen fields, in the database records. A subject search is the one that allows user to submit a subject expression that reflects his/her information requirement. Such a search is conducted on the subject field that contains one or more assigned subject headings entered by the indexer while creating the record in the database. Thus, a record will be retrieved only when user’s subject search expression exactly matches the subject heading assigned by the indexer.
7) What is meant by online searching?
The phrase online searching was originally used to describe the process of directly interrogating computer systems to resolve particular requests for information . Now the phrase is used to denote searches that are conducted by means of a local computer that communicates with a remote computer system containing databases.
8) Give three examples of online search services.
Dialog, Ovid, STN
9) What the major steps in an online information search?
The following are the major steps in an online search:
i) Study the search topic and develop a clear understanding of the information requirement.
ii) Get access to an online search service.
iii) Log on to the service provider.
iv) Select the appropriate database(s) to search.
v) Formulate search expressions.
vi) Select the appropriate format for display.
vii) Reformulate your query, if necessary.
viii)Select the mode of delivery.
10) What is the basic difference between a guided search and a command search in
A guided search is meant for novice users whereas a command search is meant for experienced or expert users. A guided search takes the user through the various stages of a Dialog search, whereas a command search expects the user to know the specific search commands and use those commands to conduct a search. A guided search is easy to use it often takes more time, and does not allow the users to create complex search expressions. However, a command search, although expects the user to know the Dialog commands, is faster and allows the users to create complex search search expressions.
11) What is difference between the following two search expressions in Dialog:
S (digital or electronic) (w) libraries
S (digital or electronic) and libraries
Both search statement will retrieve records on digital libraries or electronic libraries. In the second search, the two terms digital and libraries, or electronic and libraries can occur anywhere in the retrieved documents. Because of the proximity operator w, that specifies that the two terms should occur next to each other, the first search expression will retrieve only those records containing the phrase ‘digital libraries’ or ‘electronic libraries’, i.e., the terms digital and libraries should occur next to each other as it appears in a phrase, and the same thing will happen for the terms electronic and libraries.
12) What is a spider in the context of a web search engine?
To find information on the millions of web pages, a search engine employs special software called a spider or crawler. It is a program that automatically fetches web pages for search engines; it is called a spider because it crawls over the web.
13) What is a meta search engine? Give example of two meta search engines
Tools that allow users to conduct concurrent searches on more than one search engine. Examples: Dogpile, Mamma
14) Give examples of two web search engines that use visualization techniques for display of information on the screen
Meta Search Engine : A search engine that allows users to run concurrent searches on more than one search engine.
Online Search Services : Information providers or database producers who provide databases to be accessed in an online mode.
Spider or Crawler : It is a program that automatically fetches web pages for search engines; it is called a spider because it crawls over the web.
Web Browser : A computer program that is used to get access to the Internet, typical examples being Netscape Navigator and Microsoft Internet Explorer.
Web Search Engine : Programs that allow users to search and retrieve information from the web.
Wild Card : Wildcard Character, in computer science, a keyboard character that can be used to represent one or many characters; usually encountered with operating systems as a means of specifying more than one file by name. Example: the question mark (?), the asterisk (*), etc.
Source: IGNOU Study Material