I have not been able to find a clear issue on omitting reviews from Microdata.

I understand that Microdata values for reviews will default to a certain number when omitted, but I was wondering if it would be correct/acceptable to completely omit the review node completely.

I can see where reviews and average "star" ratings would be of help to the end user, especially for things like recipes. However, what if there are no reviews for a product or application?

To be completely clear - let's isolate this question to only software applications or extensions. What if a particular piece of software or extension was not featured on an "app store" or other site that provided reviews? Wouldn't the formats still be helpful by providing version number, download URL, compatible software - etc?

Sorry for the lengthy background, but I just don't understand why it seems that reviews must be part of a Microdata markup. Or, am I wrong in this assumption?

2 Answers 2


I am not sure of exactly what you are asking so I will try and answer it short and sweet.


Okay. I will explain. AggregateRating, Review, and SoftwareApplication are all under CreativeWork and can be nested to create a cohesive review of software items. The AggregateRating is used to wrap individual Review(s) as you are used to seeing with stars. It is the AggregateRating that provides the stars. If there are no reviews then the value for reviewCount under AggregateRating would be zero along with ratingValue and therefore no stars.

It is confusing and there are some good examples on the new. However, use the Google Rich Snippets Tool to check any example before going down that rabbit hole. There are more bad examples than good ones. Check out schema.org for details. It is as clear as mud when you look at it but with some good examples it becomes clearer.

So to answer the omitting part, you would still create the microdata markup, but use zero as I have outlined.

To answer the defaulting part, not all values default. Some have to be specified. When you create your AggregateRating and Review(s) you will have to provide some values but not all.

I think some of the confusion you are alluding to is where no one has reviewed the software item - would it be of value to the user? Generally, an item that is not reviewed has zero stars and of no real value to the user. You would be right. However, if you have experience with the software item, you can enter a review.

Does this help?

  • Yes. That helps quite a bit. I guess I am mainly very confused as to the why reviews are so integral or required for microdata format. I would think there would still be so much value to the user, whilst browsing SERPs, to see a version number and compatible software/OS types.
    – user36562
    Commented Mar 1, 2014 at 0:06
  • I will elaborate a bit further. For example, if I was looking at a driver for my logitech mouse - I would be very unlikely to review it. But, I would love to search for logitech mouse driver and in the SERPs see when it was updated, what version OS it is compatible with etc... Reviews of the driver would be irrelevant to my intent. Does that make a bit more sense now?
    – user36562
    Commented Mar 1, 2014 at 0:08
  • I think so. You want the SoftwareApplication *or other similar items) marked up so that it shows up in the SERPs. Right? You can mark it up, by most search engines are not including these things in the SERPs yet that I am aware of. I would do the mark-up anyway. It is just a matter of time. I saw some markups showing just this week that previously did not though I cannot recall what kind of markup it was. Google, for example, is working on this but I think it is a big job and will take a while to implement. It would be good to be the first to show up in the SERPs.
    – closetnoc
    Commented Mar 1, 2014 at 0:20

You are probably talking about Schema.org and not about Microdata.

Schema.org is a vocabulary (which can be used with various syntaxes, including Microdata), Microdata is a syntax (which can be used with various vocabularies, including Schema.org). (Related answers: 1, 2.)

So, Microdata doesn’t require anything like that. But Schema.org doesn’t require it either. It’s perfectly valid and allowed to specify only those properties you want. Schema.org doesn’t define required properties.

Schema.org consumers (tools, search engines, …) can, of course, "require" anything they want. For example, Google may say that they only show a Rich Snippet when particular properties are specified. That’s up to them, so it’s rather pointless to try to understand their reasons for that, as nothing can be done about it. For now, they decided it that way; it’s likely that they’ll support additional Rich Snippets in the future, so it may be the case that suddenly even "incomplete" (in Google’s view) Schema.org data will be used for displaying a Rich Snippet.

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