BOOLEAN LOGIC APPLIED TO ONLINE SEARCHING

By

Miss T.

© Janet Tillman/The Master’s College, 2004, 2007, 2009, permission is granted for non-profit educational use; any reproduction or modification should include this statement.

Venn Diagram

Set A Set B

Boolean AlgebraAlgebra x and y = numerical values

Boolean algebra x and y = classes of objects

Science of Logic based on Mathematics

Boolean Logic: any variable that can have a logical value of true or false; works with logical rather than numeric relationships

Boolean Logic is crucial to the development of twentieth century computer programming

Intersection of Set A and Set B

Set ASet B

U

= INTERSECTIONU

A B

Set B

A U B

Set A

Union of Set A with Set B

U = UNION

Set A Set B

A U B

UNION

INTERSECTION

?

Set A

Set B

U

A

B

BOOLEAN OPERATORS

• AND• OR• NOT

Set BSet A

BOOLEAN OPERATORS• AND

- Narrows the search

- Can be thought of as BOTH

- Requires that both terms be in the results

- Used for combining differing concepts

Messiah AND Christ

• the INTERSECTION of two sets

-Sometimes referred to as “All of these”

BOOLEAN OPERATORS

• OR- Broadens the search

- Used to find one term OR another

- Can be thought of as EITHER

- Used to search synonymous/closely related terms

Messiah OR Christ

• the UNION of two sets

-Sometimes referred to as “Any of these”

BOOLEAN OPERATORS

• NOT

-Narrows a search

-Used to eliminate records

-Exercise extreme caution; needed concepts may be eliminated unintentionally

Messiah

Messiah NOT Christ

Christ

Messiah

BOOLEAN APPLIED

a U b c

U

a b

c

a U b c

U

a b

c

Messiah OR Christ AND JesusMessiah OR (Christ AND Jesus)

a b

c

Messiah Christ

Jesus

Messiah OR Christ AND Jesus

Messiah Christ

Jesus

( )

Messiah Christ

Jesus

(Messiah OR Christ) AND Jesus

Messiah OR Christ OR Jesus

Messiah AND Christ AND Jesus

Messiah OR Christ AND Jesus

Messiah OR Christ OR Jesus

Messiah Christ

Jesus

Messiah Christ

Jesus

Messiah AND Christ AND Jesus

Messiah Christ

Jesus

(Messiah OR Christ) AND Jesus

Basic or Advanced

• Search engines have a Basic and Advanced search mode

• Command searching is generally performed in the Basic search mode– Commands used vary with each search engine

• Library catalog (next slide)– One free text search box– One field selection

• Advanced Search– Drop down menus “all of these” “any of these”– Multiple free-text search boxes.– Multiple field selections

Command Search in Basic

Advanced Search

Command Search in Basic

Command Search in Basic

Advanced: Command Search

Advanced: Command Search

Advanced Search: Multiple fields

Advanced Search: Multiple fields

LOGICAL OPERATORS – “AND”

• Limiting Operators

-Phrases

-Field

-Date-Type of Document

-Language

-Proximity

LIMITING OPERATORS

• PROXIMITY: NEAR or WITHIN– a restrictive AND–Designates the closeness of terms

within a source document–Designates the number of words by

which search terms can be separated–Particularly useful when concepts are

closely linked but a phrase is too narrow

w/n: within the same document where n = the maximum number of words that can come between them

Jesus w/1 Messiah

LIMITING OPERATORS

• PROXIMITY: NEAR or WITHIN

w/s: within same sentence

w/p: within same paragraph

Pre/n before term where n=designated number

Jesus the Messiah

Jesus pre/1 Messiah

Jesus w/s Messiah

Jesus w/p Messiah

LOGICAL OPERATORS – “OR”

–Means “to cut off”–Very useful

command for expanding a search concept

– Typical symbols used * ! ?

– Plurals– Variant Endings:

• ed, es, ing• banks, banking, bankruptcy

– Variant Spelling:• women/woman• color/colour• encyclopedia/encyclopaedia• judgment/judgement

•Truncation/Wildcard

LOGICAL OPERATORS – “OR”

–Related terms–Expanders–Suggested Topics

•Synonyms

– ON/OFF toggle– Preprogrammed list

of terms• Work, employment,

job, vocation

– Not exhaustive

Key to online searching:

Devise a search query that makes conscious use of Boolean operations to retrieve the desired set of records while eliminating extraneous records.

Critical Thinking Applied to Online Searching

• Select appropriate database or indexing tool– Subject Specific: ATLAReligion, ERIC, Business Source,

Health Source, etc.– Interdisciplinary: Academic Search, Opposing Viewpoints

Resource Center, Proquest Research Library, Periodical Abstracts, etc.

• Select appropriate terminology– What is unique in one database may be common in another

• Get to know the database’s – Defaults– Features – Limiting options

bill w/3 clinton or george w/3 bush

Here’s how one database will resolve this search:

clinton or george

bill within three or fewer words of clinton or george

bush within three or fewer words of clinton or george that is also within three or fewer words of bill

However, with the use of parentheses you can force the names to stay together as one search concept. For this example, you would enter:

( bill w/3 clinton ) or ( george w/3 bush)

Summing up

• Select appropriate research tools• Design appropriate search query utilizing

available logical operators• Evaluate results and revise search if

necessary

View this Tutorial

• Library Web site• Research Guides & Tutorials• Tutorials• Boolean Logic

Questions?

• See Miss T.– 1-10 Mon-Thu; 10-7 Fri

• Call Miss T.– 661-362-2201 ext. 3422

• Email Miss T.– jtillman@masters.edu

LIMITING OPERATORS

• Language-English-French-Chagatai

• Date -Specific date -Before < -After > -Range

• Type of Document-Article

-Book Review-Thesis/Dissertation-Proceedings-Manuscripts

CATALOGAuthor

Title

Subject

Call Number

SCIENCESuper Taxa

Gene Symbol

Molecular Sequence

BUSINESSSlogan

Company Name

NAICS Number

INTERNET

Page Depth

Location/Domain

Media Types(Java, Images, Script, etc.)

PERIODICALSFull-text

Abstract

Citation

Fields

DUNS Number

References Cited