The KL divergence of the document collection pairs in the DP condition fall mostly in the middle range, and is well separated from the high KL divergence of the pairs in DT condition and from the low KL divergence of the pairs in SP and ST conditions.
by simply calculating the KL divergence of a document collection pair, we can reliably predict that they are written from different perspectives if the value of KL divergence falls in the middle range, from different topics if the value is very large, from the same topic or perspective if the value is very small.