The point of it…
These word clusters help you to see patterns of repeated phraseology in your concordance, especially if you have a concordance with several thousand lines. Naturally, they will usually contain the search-word itself, since they are based on concordance lines.
Another feature in Concord which helps you see patterns is Patterns.
How it does it…
Clusters are computed automatically if this is not disabled in the main Controller settings for Concord (Concord Settings) where you will see something like this:
where your usual default settings are controlled. "Minimal processing", if checked, means do not compute collocates, clusters, patterns etc. when computing a concordance. (They can always be computed later if the source text files are still present.)
Clusters are sought within these limits: default: 5 words left and right of the search word, but up to 25 left and 25 right allowed. The default is for clusters to be three words in length and you can choose how many of each must be found for the results to be worth displaying (say 3 as a minimum frequency).
Clusters are calculated using the existing concordance lines. That is, any line which has not been deleted or zapped is used for computing clusters.