The computation is done on a per-document basis, such as each
document is scored with a value between -1 and 1. This is relevant to the
computation of the denominator of the score.
It is possible to compute the score for paragraphs and sentences for a
quanteda::corpus segmented using quanteda::corpus_reshape. Segmenting a
corpus using quanteda's helpers retain track to which document each
paragraph/sentence belong. However, in that case, it is possible that
paragraphs or sentences are scored outside the (-1,1) interval. In any
case, the of the paragraph/sentences scores averaged over documents will be
contained in the (-1,1) interval.