For example you have a folder structure as displayed to the right. With a folder structure you cannot list all documents in all "Analysis" folders. You can do this with only one folder at the time. Using meta-data, you would be able to do this without specifying a value for a project name.
Microsoft implemented this concept in SharePoint in the form of "columns". SharePoint consultants are adamant that folders should not be used anymore (or much less) and should be replaced with meta-data. The concept sounds very appealing but has some limitations (you might want to translate some of them into strengths, but I look at this from the perspective of the lazy end-user):
- The concept of multiple dimensions eludes many people. It might be that Gen-Y people over time pick this concept up easier since they have not worked in the strict folder world for that long. However I like to warn against comparing this with the easy uptake of social networking by Gen-Y and the fact that they have replaced email with Facebook, Twitter and SMS. The use there is free and for the moment only. In a business context you need to have more structure and need to keep data for a longer period of time. Note that folders are a concept that we understand from the real life. We have folders in boxes on shelves. When we lose this concept, people are a bit lost in where the document really is. We do not always need to know this. My blog is somewhere in the cloud and I am not too worried about where it physically resides. But I think SharePoint should come with a better user interface for navigation and management to give the users a better sense of control.
- In SharePoint users cannot freely create new columns. Where a folder impacts only the folder in which it is created as a sub-folder, a column impacts the whole site.
- It requires to have the right permissions. If people can't make their own columns (folders) they will feel too much locked in and will resort to using alternative places to store their documents.
- With columns you need to think ahead and define values and the required use beforehand. While many people have a document or a few documents and just want to place it somewhere that makes sense for that moment in time. If it becomes too much work, they will place it on the local C drive. If you could create columns on the fly and as easy as creating a folder and add values to columns on the fly, it might make more sense.
- When specifying in which folder and where in the hierarchy you want to create a document, you can do that using mouse-clicks. It works via a drill down mechanism and each time the number of options are limited. With columns, the selection of a value for the first column does not reduce the number of options for the second column.
- The way SharePoint works now, it is not easy to navigate using the multi-dimensional features. You need to define views for that.