Transcript 10/6/09: Truncation & Nesting in IRs

Databases & Search Engines
Wildcards,Truncation, Nesting
IS530
Dr. Dania Bilal
Fall 2009
Searching IRs
• Most IRs provide searching capabilities
using wildcards & truncation
• IRs includes Dialog and similar databases,
Web search engines and OPACs
• Purpose
– Increase number of retrieved results by
broadening a specific search
Searching IRs
Nesting
• Most IRs allow use of nesting techniques.
• Purposes:
– Retrieve more precise search results
– Avoid retrieval of “false drops” or “false hits”
• Boolean operators are executed based on their
strengths:
• NOT Strongest, processed first
• AND Stronger, processed second
• OR Strong, processed last
• Appropriate use of nesting with Boolean forces retrieval
software to process searches with specific operators
inside a ‘nest’ or ‘parentheses’ first, then combine the
results of the sets.
Nesting
• Search technique used to group similar
terms or terms that have relationships
together to increase search results
• Synonyms and related terms are usually
used to broaden a search using the OR
operator inside a nest containing two or
more terms
• Nested terms are then combined with the
AND operator
Nested Searches: Examples
(information seeking OR search strategies)
AND
(Internet OR world wide web)
Class Exercise 1.
Try the search above in Google and give the
total no. of records retrieved.
Nested Searches: Examples
(“information seeking” OR “search strategies”)
AND
(Internet OR “world wide web”)
Class Exercise 2.
Try the search above in Google and give the
total no. of records retrieved.
Nested Searches: Examples
(information seeking OR search strategies)
AND
(Internet OR world wide web)
Class Exercise 3.
Try the search above in Yahoo and give the
total no. of records retrieved.
Nested Searches: Examples
(“information seeking” OR “search strategies”)
AND
(Internet OR “world wide web”)
Class Exercise 4.
Try the search above in Yahoo and give the
total no. of records retrieved.
Nesting in EBSCO HOST
(information seeking OR search strategies)
AND (internet OR world wide web)
Without selecting any field or an operator for
the search boxes will retrieve:
1,035 results
Caution: If you misspell a word, no
correction in spelling is made.
Nesting in Dialog
*File 1: The file has been reprocessed. Dialog
accession numbers have changed. Set Items
Description --- ----- ----------? ss (information seeking or search strategies)
and (internet or world wide web)
S1 2698 INFORMATION SEEKING (ADDED 08/13/1968)
S2 3323 SEARCH STRATEGIES (ADDED 08/13/1968)
S3 16573 INTERNET (ADDED 02/23/1996)
S4 6077 WORLD WIDE WEB (ADDED 06/26/1996)
S5 963 (INFORMATION SEEKING OR SEARCH
STRATEGIES) AND (INTERNET OR WORLD WIDE
WEB)
Dialog
Searching without Nesting
? ss information seeking or search strategies and
internet or world wide web
S6 2698 INFORMATION SEEKING (ADDED 08/13/1968)
S7 3323 SEARCH STRATEGIES (ADDED 08/13/1968)
S8 16573 INTERNET (ADDED 02/23/1996)
S9 6077 WORLD WIDE WEB (ADDED 06/26/1996)
S10 8768 INFORMATION SEEKING OR SEARCH
STRATEGIES AND INTERNET OR WORLD WIDE WEB
Dialog
Nesting and Proximity
•
The most precise search to formulate on this topic in Dialog is:
? ss
(information(w)seeking or search(w)strategies) and (internet or world(w)wide(w)web)
S11
S12
S13
S14
S15
S16
S17
S18
S19
S21
S22
215883 INFORMATION
12289 SEEKING
2970 INFORMATION(W)SEEKING
18817 SEARCH
111104 STRATEGIES
3558 SEARCH(W)STRATEGIES
16573 INTERNET (ADDED 02/23/1996)
57657 WORLD
26836 WIDE S20 17244 WEB
7174 WORLD(W)WIDE(W)WEB
1023 (INFORMATION(W)SEEKING OR SEARCH(W)STRATEGIES) AND (INTERNET OR
WORLD(W)WIDE(W)WEB)
Results:
1,023 with the proximity (w)
8768 without the proximity (w) (previous slide)
EBSCO Wildcards
Two symbols are employed:
– A question mark ?
– A pound sign
#
• The
?
Wildcard symbol
– Enter your search terms and replace a single
unknown character with the ?
• Example:
– ne?t
• Will find citations containing neat, nest or next. (net will not
be retrieved because the wildcard replaces a single
character).
EBSCO Wildcards
• The # wildcard symbol
• Used in places where an alternate spelling
may contain an extra character.
– Example: colo#r
– Will retrieve all citations containing color or
colour.
EBSCO Truncation
• Truncation is represented by an asterisk (*). To
use truncation, enter the root of a search term
and replace the ending with an *.
– Example: comput* will retrieve records with the
words computer, computing, computation,
computational.
• The Truncation symbol (*) may also be used
between words to match any word (exactly as
used in Google).
– Example: a midsummer * dream will return results
that contain the exact phrase, a midsummer night’s
dream.
Wildcard in Dialog
? s wom?n
S26 43937 WOM?N
? s woman
S27 3759 WOMAN
? s women
S28 42413 WOMEN (ADDED 07/01/1966)
Truncation in Dialog
? s beef?
S29 203 BEEF?
? s beef
S30 185 BEEF
Dialog
Logoff Hold
? logoff hold
Just enter a command to reestablish your
session (this is the message you get in
Dialog when you logoff hold)
Keeps your search for 30 minutes
Once you logon again and type DS, you will
see the results of the previous search.
Truncation in Google
• Google use the * for truncation
Example 1: search strateg*
Results 1 - 10 of about 2,330,000 for
search strateg*
Example 2: search strategy
Results 1 - 10 of about 107,000,000 for
search strategy
More about Yahoo
Shortcuts for Quick Searching
For a definition: Type define followed by a word
–
Example: define “web 2.0”
For weather: Type weather followed by the location
–
Example: weather knoxville
For maps: Type map followed by the location
–
Example: map knoxville
For Yellow Pages: Type a five-digit zip code
Class Exercises
Go to Yahoo
1. Type your zip code. What did you find?
2. Type map and your location. What did you
find?
3. Type weather casablanca. What did you find?
4. Type define “information science”
Define: “information science” also works. What did
you find?