SharePoint Search - what does the Author filter mean?

If you have ever used SharePoint Search chances are that you have seen and used the "Author" filter. Author - we all know what that means, right? Well, not really. Author can actually mean different things in different contexts. In the context of the SharePoint Search the Author filter (based on the built in managed property Author) probably doesn't mean what you think it means. For example the screenshot below displays names of people that doesn't exist in our company among the Authors:

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By the end of the article you will understand why.

I kind of already knew the logic for this filter based on the behavior that I had observed throughout my years of working with SharePoint, but recently I did some digging to verify what I thought I knew. It turns out that I was right on most parts but didn't have the full picture.

Hera are some questions that you might have been asking your self:

Are the names that are presented in the Author filter equal to the "Creator by" field of a document?

Answer: No.

  • The user who first uploaded the document to a document library is always part of the Author filter, however this person is not the only one included in the Author filter.

Does Author include modifiers of a document?

Answer: Yes and no

  • It includes the latest modifier but not earlier modifiers of a document.

Example: Person A uploaded a document to SharePoint and the latest person who edited it is person B

Both A and B would be available in the Author filter.

So behind the scenes, if you look at the screenshot below, Henrik Gustafsson would actually be picked up from both last modified by, and created by - and then merged into one single Henrik Gustafsson:
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How come I only see one document, but two or more names listed under the Author filter?

Answer: Because multiple properties are picked up and then transformed to a list of unique names.

Example: Person A uploaded a document to SharePoint, yesterday person B edited the document and today person C edited the document.

A and C would be available in the Author filter, but not B.

If you look at the image below, the Author of version 2.0 would not be picked up, but number 1.0 (created by) and 3.0 (last modified by) would be:

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Ok, I understand that "Created by" and the "Modified by" fields are picked up, but I'm the only one that have worked with the document in SharePoint - what's up with that?

Answer: The Author filter also includes properties from the document itself. In the sample below you would get Henrik Gustafsson, Patrik Björklund and John Doe from the documents properties. alt

Notice how you can add "Authors" to office documents, these can be from inside the organisation or just free text. Maybe you think that's crazy or maybe you think it's awesome but that's how it is. Also mind that this means that Author names can travel from outside your organisation into your SharePoint Search Author filter.

Person D is not part of the "last modified by" or "created by", nor does it exist in the document properties, but is still showing up in the Author filter - huh?

Answer: SharePoint also extracts names from the contents of Word documents and PowerPoint presentations. So if you declare an author in the text in one of these file types, that name will be picked up.

Bottom line

I find the behavior of the Author filter interesting, it both makes sense and doesn't. It doesn't always go hand in hand with how end users handle their documents but after reading this article you can at least discuss where the fault lies (if there even is a fault).

The real issue occurs when end users don't know how it works, which is almost always the case.

Now, go spread the word to your end users - knowing how it works makes the experience better.

If you need more information on SharePoint Search and how to make use of Search in your organisation - feel free to contact us.

Delimitations

Note that different file types can have different behavior, a non-MS document doesn't have the Author properties, and for example an email maps the "from" - field to be part of the Author filter.

This article applies to SharePoint 2013 (SharePoint Server 2013 CU October 26, 2013) and SharePoint Online.