The problem is text placement. Some people, including me, opt to place the text outside the diagram and connect to it using lines or arrows. A bullseye diagram conveys the idea of a core and its subsequent layers. It is a hierarchy diagram with the center been the most important part, the core if you will.
A slide that I didn't show in the last post was a simplification of diagram I would called a Earth's Layers diagram:
|Source: Wikimedia Commons|
In essence, it is the bullseye diagram in 3D. I wanted to visualise the following layered hierarchy 1. Principles 2. Methodologies 3. Tools. At the core are the principles, followed by the methodologies, and tools as the final layer. My plan was to place the text on x-y plane.
I ended up not using the earth's layers diagram because I couldn't modified the above diagram to have only three layers. So instead I came up with this:
|Simplification of a earth's layers diagram|