The idea is to help stylistic comparisons. Suppose you're studying several versions of a story, or different translations of it. If one version uses kill and another has assassinate, you can use this function.
The procedure compares all the words in both lists and will report on all those which appear significantly more often in one than the other, including those which appear more than a minimum number of times in one even if they do not appear at all in the other.
How to do it
1. Open a word list.
2. In the menu, choose File | Compare 2 wordlists.
3. Choose a word list to compare with. You will see the results in one of the tabs at the bottom of the screen.
The minimum frequency (which you can alter in the Controller, KeyWords Settings tab ) can be set to 1. If it is raised to say 3, the comparison will ignore words which do not appear at least 3 times in at least one of the two lists.
Choose the significance value (all, or a p value from 0.1 to 0.000001 or what you will). The smaller the p value, the more selective the comparison. In other words, a p setting of 0.1 will show more words than a p setting of 0.0001 will.