Scope

• Each record in Dialog has many fields, such as title, author, subject headings, date, text, abstract, etc.
• Every word, every piece of numerical data in these fields is tracked in field-specific indexes.
• The indexes enable the searcher to search the contents of specific fields, which facilitates the targeting, limiting, or narrowing the set of resulting records (precision).

Types of Field/Index Commands

• Dialog provides two commands to specify the fields/indexes to be searched on:
  • Suffixes
    • These are used in the form:
      • s <search term>/suffix
    • NOTE: These are the Basic indexes, which are searched when no specific fields are selected to be searched in the search statement.
  • Prefixes
    • These are used in the form:
      • s prefix=<search term>
    • NOTE: These are the Additional indexes. They are not searched when no specific fields are selected to be searched in the search statement.

Example Field/Index Commands

Field/Index	Format	How Field Is Indexed	Example, Notes
title	/ti	word only	twister/ti
author	/ab	word only	doesn't recognize punctuation eg. cat's = cat s cat/ab
descriptor	/de	word and phrase	cat/de
journal name	jn=	phrase	jn=vanity(w)fair
company name	co=	phrase	co= Amgen
geographic name	gn=	phrase	gn= us
document type	dt=	phrase	dt=book
publication date	pd=	phrase	pd=910423 pd >=1992 pd < 9112?
publication year	py=	phrase	py=1996 py=1988:1989
publication year	/nnnn		/1996
language	la=	phrase	la=eng
English	/eng		s4/eng
fulltext	/fulltext		s2/fulltext
NOTES: There are many more Indexes and Limiters. The specific ones available depend upon the database being searched. This is why it is important to look at the Bluesheets for the databases you are going to search.

Scope

• Suffix codes are used to restrict retrieval to specified basic index fields of a record.
• The basic index contains terms from subject-related fields.
• Use of suffixes is optional, because the basic index fields are what are searched when you put in search terms without any suffixes or prefixes. On the other hand, specifying the specific field you expect the terms you are searching for to be in gives you more precise control and, hopefully, targets and constrains the set of returned records.
• Specific fields and codes vary according to the database, so you have to check the Bluesheets for each database to determine which codes are available, though there are a variety of fields common to most databases.
• In Telnet, to learn what fields are in a particular database, type help field <# of database>

Common Suffix Codes

Remember that not all of these may be used in all databases.

Suffix	Format	Examples, Notes
Descriptor	/de	ss (physicist? or astrophysicist?)/de NOTE: These are standard terms in the thesaurus for an individual database. Unfortunately, you may have to get the thesaurus from the database provider to determine what are suitable descriptors. These terms may or may not be consistent with the Library of Congress Subject headings/Authorities.
Identifier	/id	ss space(w)shuttle/id NOTE: These are "uncontrolled" terms that are largely derived from the indexing of the individual words in the documents in the database. Check the bluesheets to see if the ID field is available.
Title	/ti	ss england and unicorns/ti
Abstract	/ab	ss southwest(w)airlines?/ti,ab
Publication Year	/py	s hurricanes/1998
Note	/nt	s frequency/nt
Text	/tx	ss (frequency(8n)rather)/tx
Section Heading	/sh	s ocean/sh

Using Multiple Suffixes

• Multiple suffix codes can be used, with each separated by a comma ", ".
• Example: s southwest(w)airlines?/ti,ab

Scope

• Prefixes are codes that are used to search additional indexes.
• These indexes are not part of the Basic Index, which is searched when:
  • No codes are used.
  • When Suffix codes are used.
• Specific fields and codes vary according to the database, so you must check the Bluesheets for each database to determine which codes are available.

Example Fields

Fields	Format	Examples, Notes
Author	au=	s au=king, stephen
Company Name	co=	s co=apple computer
Corporate Source	cs=	ss cs=electronic frontier foundation
Document Type	dt=	s dt=review
Journal Name	jn=	s jn=content
Language	la=	s la=tibetan
Publication Date	pd=	s pd=981228 (Note: yymmdd format)
Publication Year	py=	s py=1998
Sales	sa=	s sa=>10b (Note: see below)
Update	ud=	s ud=3288

 

Numerical abbreviations:

• k = thousand
• m = million
• b = billion
• t = trillion