Oliver asked via E-Mail on how to do a proper AggregateRating as he has seen that his competitor is using it as well. In this post I will show you how to create a proper aggregateRating by using snip –  The Structured Data and Schema WordPress Plugin.

What is the difference between aggregateRating and reviewRating?

First of all you need to understand that there are two main rating types that were defined by the schema.org working group. The first one is the reviewRating and the second one is the aggregateRating. The reviewRating (as the name would suggest) is used if you – as the author of a post – wants to give a rating to something you wrote about. For example if you wrote a blog post about the latest iPhone, you would use the reviewRating to rate the phone.

The aggregateRating property however is used if an audience rates something. For example if you’re using a Comment Rating Plugin for WordPress that allows users to rate your blogpost content then you could use the cumulated values of the rating for the aggregateRating property.

Differences in properties

A reviewRating needs at least the following properties:

• bestRating
• ratingValue
• worstRating

In case of the blogpost about the iPhone (that I’ve mentioned above) you could give the following values to the properties:

• bestRating = 5
• ratingValue = 4
• worstRating = 0

In other words: you have the iPhone a rating of 4 out of 5 where 0 is the worst rating that could be achieved.

The aggregateRating needs one more information:

• bestRating
• ratingValue
• worstRating
• ratingCount

Lets say three different users have rated your content:

• User 1: 4 out of 5
• User 2: 3 out of 5
• User 3: 5 out of 5

You have to calculate the average rating so that it can be used inside the aggregateRating properties. In our case we have (3 + 4 + 5) / 3 = 4. So the properties need be filled like this:

• bestRating = 5 (the best rating that can be achieved)
• ratingValue = 4 (the average rating value)
• worstRating = 0 (the worst rating that can be achieved)
• ratingCount = 3 (because three users have rated)

How to create ratings using the Rich Snippets Plugin

1) Add a reviewRating to a Thing

Now open up one of your blog posts and add a snippet. In our example we use the Review main type:

2) Fill the values

As you can see in the next image, we’ve filled the values according to our example from above. We just used the text fields:

And that’s pretty much it!

3) In case of the aggregateRating: Fill the values accordingly

Don’t forget to save your settings!

How to show stars in search results

A few month back, Google supported many schema classes (like BlogPost, Article, etc.). However at this point in time, Google only shows stars for certain schema types only: A Recipe-, a Product- or an EmployerRating. Google tends to changes things frequently, so you should check back with the search gallery to see what types are currently supported.