cfischer83

Does your website utilize categories and tags? Does it use custom taxonomies? If so, this plugin will find similar content 
based on all your taxonomies. There are two ways to show related posts within your page.
<ul>
<li>The first way to show related content on your post is to use the widget provided. This only works when is_single() is true</li>
<li>The second way to show similar content on your site is to use the pk_related_return($post->ID); function which can be 
called programmatically anywhere you wish!</li>
</ul>
The Widget included with this plugin gives you the option to limit the amount of posts; it allows you to determine which 
fields to show: Featured Image, Author, Date, and Excerpt (Title is required); it allows you to determine which 
variant of the featured image to show: thumbnail, medium, large, or full. As of version 2.0, you can now decide whether the 
‘similar posts’ sorting prefers posts that are newer or posts that were created closer to the date of the post you’re 
viewing.
If you find the Widget doesn’t meet your needs or is too limiting, you can call the functionality programmatically using 
this function:
<pre><code>pk_related_return($post->ID, $args);
</code></pre>
Where $post->ID is the ID of the post for which you are wanting to show related articles.
The $args parameter is an array with the following values available to you (more coming soon):
<ul>
<li>posts_per_page (int defaults to 5)</li>
<li>thumbnail_size (string consisting of one of these values: “thumbnail”, “medium”, “large”, “full”. Defaults to thumbnail).</li>
<li>sort_prefer (string consisting of one of these values: “newest”, “closest”. Defaults to newest).</li>
</ul>
An example might be:
<pre><code><?php
$args = array (
 'posts_per_page' => 6,
 'thumbnail_size' => 'medium',
 'sort_prefer' => 'closest'
);
</code></pre>
The return value of pk_related_return is an array of objects that includes most of the fields within WordPress’s posts 
table plus permalink and featured image.
Future Additions:
Allow the user to specify only certain content types (posts, pages, custom) in a request. This would allow you to specify 
only products get returned, or only blog posts. This would only be an issue if content types share taxonomies.

Similar Posts Ontology

Show a list of related posts that are similar to another post.

Recmnd allows you to show related content to your readers. The recommendations are real-time and change when you update your content or when you publish new articles. All recommendations are served via a widget and you control its style, the information shown for each suggestion, the number of displayed recommendations, the time period of the recommendations, and the depth of the recommendation analysis. In order to use the Recmnd service you must register for an account: <a href="http://www.recmnd.com/plans/" rel="nofollow ugc">http://www.recmnd.com/plans/</a>. This plugin works with our trial accounts as well.
For more information, please visit the Recmnd website at <a href="http://www.recmnd.com/" rel="nofollow ugc">http://www.recmnd.com/</a>.

Recmnd

The plugin allows you to use the Recmnd service (www.recmnd.com - automatic recommendations) with your WordPress blog without coding.

Similar Posts Ontology vs Recmnd