These vector-based visualizations were created with RAWGraphs.
This alluvial diagram illustrates correlations between categorical dimensions, showing visual links to the number of elements sharing the same category. The filename for a particular document is shown on the left, the correspondent is on the right, and the machine-extracted feature is in the middle.
This circle packing diagram illustrate hierarchies and comparable values. This diagram shows the most frequently mentioned machine-extracted features by correspondent.
This cluster dendrogram illustrates the distribution of a hierarchical clustering of elements. This diagram tree show the main machine-extracted features clustered by correspondent (and filename).
The sample data set used to create these visualizations can be downloaded here.