Luis A. Ochoa

Relevant Search will provide contextual search and listing the results based on relevance. It automatically replaces the default WordPress search.
No configuration required.
<h4>MySQL Documentation</h4>
<ul>
<li><a href="http://dev.mysql.com/doc/refman/5.6/en/fulltext-search.html" rel="nofollow ugc">Full-Text Search Functions</a></li>
<li><a href="http://dev.mysql.com/doc/refman/5.6/en/fulltext-natural-language.html" rel="nofollow ugc">Natural Language Full-Text Searches</a></li>
<li><a href="http://dev.mysql.com/doc/refman/5.6/en/regexp.html" rel="nofollow ugc">Regular Expressions</a></li>
</ul>

Relevant Search

Relevant Search replaces the default WordPress search with relevant results.

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Adjust WordPress search results to order by relevance, not by date.
Just install in the typical WordPress plugin way and it will adjust searches automatically, no settings needed.
Also adds a relevance score to the title of search results, which you can style via CSS (see FAQ).
Version 2.0 gives you more control, including:
<ul>
<li>Hide relevance scores in results titles and/or admin</li>
<li>Auto style relavence scores. So you don’t have to add float:right to your CSS!</li>
<li>Highlight search terms </li>
<li>Custom excerpt centered on the search terms found</li>
</ul>

Search Relevance

Adjust WordPress search results to order by relevance, not by date.

Relevant Search vs Search Relevance