Update: I've made a couple of updates related to new SharePoint 2010 capabilities.
There are many posts out there extolling the virtues of using metadata over folders for organizing information in SharePoint 2007. I certainly believe that metadata is a great tool for for classifying information, but it is incorrect to ask whether to use folders or metadata to organize information. Rather, it is more appropriate to ask when to use folders and when to use metadata. This post is not intended to be an in-depth discussion of information architecture. Instead, I wanted to provide a few pointers on when to use folders and when to use metadata. The following is a brief comparison between folder and metadata capabilities in the SharePoint platform. The context of the comparison is only out-of-the-box (OOTB) capabilities. With enough custom code, folders and metadata could be made equivalent.
|Security||Folders can be used to propagate permissions and control the access to the resources the folders contain.||None.|
|Content Type Order||Folders can control which content types users can create using the New menu on the list toolbar. Folders can also control the order in which the content types appear in the menu.||None.|
|Navigation||Folders are intrinsically part of the navigational infrastructure in the SharePoint platform.||Metadata can be used to control navigation, but this requires creative approaches. List View web parts showing filtered list views can provide metadata-based navigational capabilities. While this requires no custom code, it can be labor intensive to add the web parts to a large number of pages. Additional metadata-based navigation can be accomplished through custom code. |
SharePoint 2010 Update: SharePoint Server 2010 supports the use of metadata-based navigation for files in document libraries and list items.
|Url||Folder names form portions of the Urls of the SharePoint resources the folders contain.||None.|
|Tools Support||Most Microsoft and 3rd party tools inherently know how to work with folders in the SharePoint platform.||Metadata support in 3rd party tools is spotty. While a tool from one vendor will generally understand how to handle its own metadata, the tool will generally not understand how to handle the metadata from another vendor’s tool. This can make it challenging to incorporate metadata from multiple vendors’ tools into a single SharePoint information architecture.|
|Search||None.||Metadata is indexed by SharePoint search and will return results based on keyword searches. SharePoint Server also supports promoting selected metadata to searchable properties. |
SharePoint 2010 Update: SharePoint Server 2010 and FAST Search for SharePoint supports using metadata to refine search results.
|Sort||None.||Metadata can be used to control the order in which items are displayed in list views.|
|Filter||List views can be configured to show only the list items contained within a folder and its sub folders.||Metadata can be used to control the which items are displayed in list views.|
|Group||None.||Metadata can be used to group list items together in list views. List views limit grouping to two hierarchical levels.|
As you can see, folders and metadata each have their own capabilities and affects on a SharePoint information architecture. A proper SharePoint information architecture will contain the judicious use of both folders and metadata.