Types of Databases
1. Bibliographic. Each record is a reference or citation (many
also include a summary or abstract) to a publication, magazine
or journal article article, news story, patent, conference
paper, etc. Examples: #1, ERIC; #47, Magazine Index.
2. Directory. Each record gives factual information about
companies, organizations, products, etc. Examples: #114,
Encyclopedia of Associations; 3516, D & B--DUNS Market
Identifiers.
3. Numeric. Each record is a table of statistical data, often
with text added. Examples: #575, Donnelley Demographics;
#82, PTS U.S. Time Series.
4. Full-Text. Records include the complete text of magazine
articles, newswire stories, encyclopedias, etc. Examples:
#258, AP News; #180, Academic American Encyclopedia.
Elements of a DIALOG Search
1. Commands
2. Descriptors
3. Boolean Operators\Logical Connectors
4. Proximity Connectors
Basic Commands
Begin or B Used with a database number to specify the
database to be searched. Example: b 258
Select Steps or SS Used with descriptor(s) to determine
the number of records in the database which contain the
descriptor(s) and store them in a set. Example: SS censorship
Combining or SS SS can also be used to combine descriptors to
further search for records. Example: SS s3 and censorship
Type or T Requests that search results be displayed. It
is followed by a set number, format number and a range of
records. Example: T 4/2/1-5
Logoff Used to disconnect from DIALOG system.
Logoff Hold Used to disconnect from DIALOG and have search
held for at least ten minutes.
Display Sets or DS List all the sets created since the last
BEGIN command.
EXPAND or E Displays a section of the database index for
search term verification and viewing of index entries.
Combining or C Searches two or more previously established
sets. Example: C 4 and 7
SAVE Stores the strategy (all commands that produced sets),
and assigns a Search Save number for later reuse.
SAVE TEMP Same as SAVE command, but is automatically
released after seven days.
EXECUTE STEPS or EXS Followed by a Search Save number,
causes Search Save to be run, creating sets with search results
for that database.
RECALL Used to list Search Saves (RECALL TEMPS, RECALL
SAVES). Also used to display a specific Search Save strategy.
Example: RECALL TC012
RELEASE Used to erase a Search Save from DIALOG system.
Example: RELEASE SB014
SELECT FILES or SF Creates group of databases to be searched
in DIALINDEX, file #411. Example: b 411/sf busnews/ss tufsyn
Types of Descriptors
Fixed or Controlled Vocabulary Example: #1, ERIC
Uncontrolled Vocabulary (all terms except nine stop words: an,
and, by, for, from, of, the, to, with) Example: #258, AP News
Boolean Operators (See: Logical Operators--Summary)
and Narrows search
or Broadens search
not Eliminates a portion of the records
Proximity Connectors
() or (W) Requires word adjacency and specified word order.
(nW) Allows for a maximum of "n" intervening words. Also
can be used with terms containing punctuation of any kind.
Example: fuel(w)alcohol fuel(#w)alcohol
(N) Requires word adjacency without regard to word order.
(nN) Allows for a maximum of "n" intervening words.
Example: fuel(n)alcohol fuel(5n)alcohol
(F) Requires terms to be in same field with record.
Example: fuel(f)alcohol
(L) Requires terms to be "linked" within same descriptor
phrase.
Example: fuel(L)alcohol
Nesting Use of parentheses to group terms for processing
prior to the processing of terms outside the parentheses. It
does not speed actual processing time. It is simply a shortcut
when entering SELECT commands. Example: ss (elderly or aged)
and (diet or nutrition)
Truncation Used to search on a word stem to retrieve all
words with variant endings. Types: right-hand unlimited
truncation (e.g., librar?); right-hand limited truncation
(e.g., librar??? ?); internal (e.g., wom?n).
Use of Blue Sheets
Sections Include: File Description; Subject Coverage; Sources;
DIALOG File Data; Origin (producer); Sample Record; Search
Options (Basic Index; Additional Indexes; Limiting); Format
Options; Direct Record Access. See: National Newspaper Index.
Prefix Symbols Represent additional indexes beyond Basic
(subject) field. Typical examples (there is some degree of
variance between databases):
AT= Article Type
AU= Author
JN= Journal Name
BN= International Standard Book Number (ISBN)
DC= Descriptor Code
ED= Edition
LA= Language
LC= Library of Congress (LC) Card Number
PD= Publication Date
PN= Product Name
PU= Publisher
PY= Publication Year
SE= Series Title
UD= Update
Examples: SS AU=HEMINGWAY; SS AU=HERSHEY, ROBERT?;
SS PY=1982 : PY=1985
Format Options Must be consulted prior to employing the
Type command. Vary from one database to another. Typically
designated format numbers: 1, DIALOG Accession Number;
3, Bibliographic Reference; 5, Full Record; 6, Title Only;
8, Title and Indexing Terms. Example: T 6/5/1-5 (requesting
online printout of full record of five most recently published
entries from set #6 of search).
Sample Searches
ss censorship and elementary schools
s1 216 censorship
s2 962 elementary schools
s3 34 censorship and elementary schools
ss s3 and libraries
s3 34
s4 116 libraries
s5 3 s3 and libraries
1) Alternative: SS censor? and elementary()school? and librar?
2) Variations in search strategies
s electric()vehicle?/de High Precision/
115360 electric/de Low Recall
7125 vehicle?/de
s1 1 electric(w)vehicle?/de
s electric()vehicle?/de,ti
119368 electric/de,ti
10784 vehicle?/de,ti
s1 351 electric(w)vehicle?/de,ti
s electric()vehicle?
142170 electric
21166 vehicle?
s1 727 electric(w)vehicle?
s electric(1n)vehicle?
142170 electric
21166 vehicle?
s1 838 electric(1n)vehicle?
s electric(5n)vehicle?
142170 electric
21166 vehicle?
s1 984 electric(5n)vehicle?
s electri? and vehic? Low Precision/
175040 electri? High Recall
21816 vehic?
s1 3098 electri? and vehic?
Appendix B: Sampling of Search Techniques to be Used in Lab
Exercises*
Commands
b (begin)
ss (select steps)
ss (combine sets and descriptors)
c (combine sets)
t (type)
logoff (diaconnect)
logoff hold (disconnect; search helf at least 10 minutes)
ds (display sets
e (expand)
save (stores prior work in a given database)
save temp (like SAVE, but released after 7 days)
exs (execute steps)
recall (lists search saves)
release (erases a search save)
sf (select files; part of DIALINDEX)
Boolean Operators
and (narrows search)
or (broadens search)
not (eliminates a portion of the records)
Proximity Connectors
( ) or (W)
(nW)
(nN)
(F)
(L)
Additional Operations
Nesting
Truncation
--right-hand unlimited
--right-hand limited
--internal
Prefix Symbols
--author (au=)
--journal name (jn=)
--publication date (pd=)
etc.
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*Although derived from the DIALOG system, many other online
and laser optical vendors utilize all or most of the same
techniques.