Adventures in the land of metadata: should I use a Lookup or a Choice Column?

Metadata Options: Choice vs. Lookup and Managed Metadata vs. Local Metadata

I'm working on a project where we are re-architecting a folder-intensive document library structure to a metadata-centric library structure as part of a migration from SharePoint 2007 to SharePoint 2010. For a variety of reasons, we are not using managed metadata (for now). One of the interesting choices we're reviewing is whether to make our document attributes Choice or Lookup columns. Here are some of the factors we're evaluating and which column type is typically the better choice for each evaluation criteria.

Both Choice and Lookup columns allow you to create a controlled list of values for an attribute. But there are pros and cons to both choices so it's important to think about both your end users and your solution objectives when you decide which type of column to create.

Click the link for the discussion of choice vs. lookup columns: Pros and Cons of Choice versus Lookup Columns. (I couldn't get the table to format nicely in my blog, so you'll need to link to the Word document on my web site to see the content.) The table in the document lists several criteria to consider when you are thinking about choosing a Choice or a Lookup column type and describes how each alternative option addresses the criteria and indicates which option "wins" for each one.

Some of the trade-offs in user experience and value maintenance might be different if we add managed metadata to the mix. And, of course, our users would really like the benefit of hierarchical metadata for tagging. There are a couple of reasons managed metadata has been ruled out as an option for now at this client:

• The organization does not have a mature SharePoint infrastructure or governance plan, including a set of clearly defined roles for the village it takes to effectively maintain and govern a well-managed SharePoint 2010 deployment. They will get there, but they are not there yet.
• We are migrating a lot of folder-based document content from existing SharePoint 2007 sites and we don't have the benefit of a third-party migration tool. Site owners are actually looking forward to breaking the folder paradigm and using metadata to organize documents. (This is a total first for me - every single site owner we interviewed as part of the metadata architecture design process "gets" the concept of metadata and immediately saw the value of metadata over folders.) However, the only user-friendly way to add metadata to lots of documents at one time if you don't have a third-party tool is to "bulk edit" in Datasheet view. Unfortunately, you can't edit managed metadata in a datasheet view so another reason we are not pushing to instantiate the managed metadata service is that it will add a delay to the conversion process that we can't afford to incur.
• Managed metadata has some "gotchas" that need to be considered. Check out this article for a great review of some of the limitations of managed metadata.

Bottom line: as with most things SharePoint, there is no definitive right or wrong answer about what type of metadata column you should create. In our solution, we are using a combination of both based on our assessment of the importance of each evaluation criteria in the solution. Since we are making different choices in different places, we are creating rock-solid design documentation so that the solution owners understand why various decisions were made and have a clear path to maintain the solution going forward.

• Microsoft
• Collaboration
• choice columns
• lookup columns
• managed metadata
• SharePoint 2010