@cam 1) you create a number of bins. Use discretion, but more than a dozen looks more professional in visualizations.
2) slot different thoughts into bins. Use relevant thought attributes, e.g., depth, color, sharpness, profoundness etc.
3) count how many thoughts per bin. Normally it should be an integer number in all bins.
4) compute a suitable diversity index. Stick with known simplistic choices rather than signaling sophistication.