I needed a way to re-use a view model, and to know which of the fields (if any) were missing values. The reason behind this was that we are developing an application where all the fields are ultimately required, but the user may not finish entering all the fields in one sitting. They may need to come back and fill in certain data items later. The multiple views are all combined into a dashbaord for each item, and I wanted to know which of the fields were missing values so I could show something like 4/15 so they would have an idea of how many fields they had left over. If there is a better way of doing this, I'd love to know.