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Service Highlights: Library Guides

Library Guide 10: Database Searching Techniques

All but two (Info Trac and Ethnic Newsatch) of the CD-ROM databases in the library use the same software and search techniques.Therefore ,once you learn how to search one database, you can transfer the knowledge to the other databases. The examples used in this guide are generic in nature; only your search statements will differ , depending on the topic. Whenever necessary, feel free to ask a librarian for assistance in searching the databases. They're at the reference desk to help.

RECORDS AND FIELDS

The majority of our databases are bibliographic, not full text. This means that you do not get entire articles, but only citations and abstracts of articles.The information in bibliographic databases is in the form of records. The records in turn are composed of fields such as TI(titile of article), AU(author), JN or SO ( name of journal), PY (publication year), AB ( abstract or summary of the article), DE(descriptors or subject headings).

SEARCH STATEMENTS

Search statements are composed of key or significant words which you expect to appear in the record and, therefore, should bring out the desired information. These search statements are always entered at the FIND prompt. For example, if you were looking for information on how welfare reform is going to effect the homeless situation in New York City, the key words would be :
      WELFARE REFORM        HOMELESS       NEW YORK CITY

A friendly warning ! Beware of typos ! The computer will look for the keywords exactly how you typed them. If you get zero results , check your spelling. The computer will not correct spelling errors.

BOOLEAN OPERATORS

Once you have identified the key words, you must tell the computer what the relationship is between these keywords. This is done by using the boolean operators AND, OR, NOT.

The AND operator is placed between the two or more terms you want to appear in one record. In the welfare example we would place the AND operator between the three key terms because they all need to be present in the record. The search statement would look like this (the order of the search term is not important) :

      FIND : WELFARE REFORM AND HOMELESS AND NEW YORK CITY

The computer will bring up the records in which all of the term appears somewhere in the record. The AND operator narrows the search. The more term you string together with AND, the less likely it is taht all terms will appear in the records , therefore , you will get fewer records.

The OR operator is used when you want one or another term to appear in a record. Use the OR operator when you wish to search for synonyms or broaden the search.. If you were looking for information on either shelters or soup kitchens, the search statements would look like this :

     FIND : SHELTERS      OR      SOUP KITCHENS

The NOT operator is used when you want the first trem but not the secound term to appear in a record. For example, if you were looking for information on New York States, but not New York City, the search statement would look like this:

     FIND :      NEW YORK STATE    NOT     NEW YORK CITY

Boolean operators can be mixed within a search satetment , however, bear in mind that the AND operation is always performed first by the computer. Therefore , if you were looking for information on either soup kitchens or shelters in New York City, you have to place your OR operation within parentheses. If you don't use the parentheses, the computer will interpret your search statement to mean shelter anywhere and soup kitchens in New York City.

     FIND :   ( SHELTERS OR SOUP KITCHENS)   AND      NEW YORK CITY.

FREE TEXT SEARCHING VS FIELD SPECIFIC SEARCHING

You can the computer to search for your terms either throughout the record or in certain fields.If you do not specify a field , the computer will look for those terms throughout the record. this is called a free text search. On the other hand , if you ask for the term(s) to appear in a certain field (s) , the computer will only look for the term (s) in that field (s). Obviously, you will receive more records with a free text search than a field specific one. However, many of the records may not be as relevant.

Most of the time specific searching is done by typing the word IN between the search term and the two letter field code. For example :

     FIND : HOMELESS SHELTERS IN TI
     FIND : SMITH - JOAN IN AU

When searching for records published during certain periods, use the PY ( publication year) field code followed by the equal sign (=) and the year or a range of years. For example :

     FIND : SOUP KITCHENS AND PY=1996
     FIND : HOMELESS SHELTERS AND PY= 1990-1996


DESCRIPTOR SEARCHING

You may be faced with a situation where you rceive too many irrelevant records.Knowing how to effectively narrow down a large number of records to a manageable size and retain relevant records is a very powerful and t8ime saving tool.
Most often this is done by searchinng the descriptor field. This is a form of specific searching mentioned above. The descriptor field contains subject headings which describe the intellectual content of the article. Therefore, if you ask the computer to look for terms in the descriptor field, it is more likely that the results are close to what you are looking for.Descriptor searching is done like any other field specific search. Type the word IN between the term and the field code DE ( in MEDLINE the field code is MESH). For example :

     FIND : HOMELESS IN DE

TRUNCATION

If you want the computer to search for a term with its various endings, an asterik ( * ) can be placed on the trunk of the word. For example , truncating the word "shelter" will retrieve records which include the terms shelter, shelters, sheltered, sheltering.

       FIND : SHELTER *

PRINTING

The records can be printed on the printer connected to the terminal by either pressing "P", "F6" , or by highlighting the print command at the bottom of the screen and pressing ENTER . The printer will print the records in the order they appear on the screen . If you wish to print only certain records , mark the records before executing the print command. This is done by placing the cursor on the record to be marked and highlighting the mark record command (bottom of the page ) and pressing ENTER. Only the records you marked will be printed. The mark record command is the fiorst command listed at the bottom of the page and is usually already highlighted - if so , you only need to press ENTER ( While the cursor is on the record) to mark the record.

LOCATING JOURNALS IN THE LIBRARY

After you have recived a print out , you must determine whether the library subscribes to the journals in which the articles appear. To do so , check the book called LIU PERIODICALS located near the Reference Desk on the 3rd floor of the library and at the periodicals desk on the 4th floor . If the name of the journal is not listed, we do not own that periodical , and you must either go to another library or take advantage of our interlibrary loan service.

Some databases contain citations to articles in books. Check the title catalog to find out if the library owns the book.

 
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