This would make an interesting story starter! Reminds me of inspiration for making mind maps to see someone's understanding of a concept.allison robertson
I'd recommend http://www.lucidchart.com for education. Offers a lot more features than Diagram.ly but also gives their most premium accounts away free for teachers and students at http://www.lucidchart.com/education !
This is a nice site for having students do thinking maps, which is how I will use diagram.ly.Jerilyn Cleere