<h2>Boolean Logic</h2>
<p></p>
<p>Boolean operators allow you to search for combinations of words or phrases. Operators are used to broaden or narrow the search by combining words or phrases. Boolean searching can be used when searching the internet or online catalogs and databases; however, it is important to take notice of specific database requirements since many have their own Boolean template.</p>
<p>Boolean logic allows you to broaden or narrow your search by combing words or phrases using the Boolean operators <strong>AND,</strong> <strong>OR,</strong> and <strong>NOT.</strong></p>
<p>The results of performing Boolean searches are illustrated by the diagrams below (called Venn diagrams). The diagrams show graphically how using the <strong>AND</strong> operator narrows a search, using <strong>OR</strong> broadens a search and using <strong>NOT</strong> excludes material from a search.</p>
<p></p>
<table bgcolor="#ffffff" border="1" width="100%" cellpadding="1" cellspacing="2">
<tr>
<td><strong>Operator</strong></td>
<td><strong>Example Search</strong></td>
<td><strong>The search will find...</strong></td>
<td><strong>Venn diagram</strong></td>
</tr>
<tr>
<td><a href="/id0904f67a80544b66" target="_blank"><strong>AND</strong></a></td>
<td>women <strong>AND</strong> marketing</td>
<td>
items containing "women" and "marketing." <strong>AND</strong> narrows a search, resulting in fewer hits.
<ul>
<li>Use <strong>AND</strong> to combine two ideas when both are important to our search</li>
</ul>
<p></p>
</td>
<td><span style='font-size:10.0pt;font-family:Arial; mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:AR-SA'><!--[if gte vml 1]><v:shapetype id="_x0000_t75"
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style='width:81.75pt;height:56.25pt'>
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o:href="http://library.duke.edu/services/instruction/libraryguide/images/andvenn.jpg"/>
</v:shape><![endif]--></span><img height="75" border="0" width="109" alt="" src="/id0904f67a805111d9" /></td>
</tr>
<tr>
<td><a href="/id0904f67a805428a1"><strong>OR</strong></a></td>
<td>global warming <strong>OR</strong> greenhouse effect</td>
<td>
items containing either "global warming" or "greenhouse effect" or both. <strong>OR</strong> broadens a search, resulting in more hits.
<ul>
<li>Use to include synonyms or alternate terms in your search.</li>
</ul>
<p></p>
</td>
<td><span style='font-size:10.0pt;font-family:Arial; mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:AR-SA'><!--[if gte vml 1]><v:shapetype id="_x0000_t75"
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style='width:83.25pt;height:57pt' filled="t" fillcolor="#36f">
<v:imagedata src="file:///C:\DOCUME~1\raschb\LOCALS~1\Temp\msohtml1\03\clip_image001.jpg"
o:href="http://library.duke.edu/services/instruction/libraryguide/images/orvenn.jpg"/>
</v:shape><![endif]--></span><img height="76" border="0" width="111" alt="" src="/id0904f67a805111f5" /></td>
</tr>
<tr>
<td><a href="/id0904f67a805428a0"><strong>NOT</strong></a></td>
<td>Caribbean <strong>NOT </strong>Cuba</td>
<td>
items containing "Mexico" but <strong>NOT</strong> "New Mexico." <em>Caution!</em> It's easy to exclude relevant items.
<ul>
<li>Excludes records containing the second term.</li>
</ul>
<p></p>
</td>
<td><span style='font-size:10.0pt;font-family:Arial; mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:AR-SA'><!--[if gte vml 1]><v:shapetype id="_x0000_t75"
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</tr>
</table>
<p style='mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0in; margin-bottom:1.0E-4pt; mso-pagination:widow-orphan; font-size:11pt; font-family:"Calibri", "sans-serif"; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; '><span style='color:green;mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0in; margin-bottom:1.0E-4pt; mso-pagination:widow-orphan; font-size:11pt; font-family:"Calibri", "sans-serif"; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; '>For additional assistance contact Lydia Jackson, Instruction Librarian (<a href="mailto:ljackso@siue.edu" style='mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0in; margin-bottom:1.0E-4pt; mso-pagination:widow-orphan; font-size:11pt; font-family:"Calibri", "sans-serif"; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-style-noshow:yes; mso-style-priority:99; color:blue; text-decoration:underline; text-underline:single; '>ljackso@siue.edu</a> or 618-650-2604) or the Information Desk (618-650-INFO).</span></p>
<p></p>
<p></p>
<p></p>