Compound Objects or not to Compound Objects...

I am developing architecture that I can see the benefit of using compound
objects. Here is a small example..


 


ProjectObject:


   Properties:


      ProjectName as string


      PictureGroups as IList(of PictureGroupObject)


      ProjectImages as IList(of ImageObject)


 


PictureGroupObject:


   Properties:


      Name as String


      PictureGroupImages as iList(of ImageObject)


 


ImageObject:


   Properties:


      Name:


      Image as FileInfo


 


I know this is not the best example, but this is what I am after. I am
trying to figure out how I would update a specific object that is inside a
collection and at the same time ...