This case study demonstrates:

1. It is practical to use tree-merge.com to merge multiple large real-world category systems into one.
   • Although the demo only shows input trees with around 60 nodes, tree-merge.com was specifically designed to handle the mapping of 5000+ nodes per input tree.
2. A GUI (Graphical User Interface; Visual data representation) is essential in allowing a human user to understand and edit mappings.
   • Mappings can get complicated and would be difficult to understand if they were defined only with text based code. In order to leverage the human users knowledge to map the category systems into one, a visual representation and seamless navigation is required.

Here are the screen shots that show the mapping process. There are 4 input trees, each with between 2 and 5 thousands nodes.