This scope option is only available for Term-chunk, Chunk-term, Query with Terms, and Query with Chunks searches. It is available for the CSV XY-charts.
When the LSA component returns results for these searches using this scope option, it will report the correlation value and whether or not the term is actually present in the chunk.
Terms will frequently have strong term-chunk correlations with locations where the term is not present. Words belong to semantic networks and LSA Term-chunk correlations actually detect the presence of the word's semantic network.
This is potentially very interesting for investigating the difference that terms make in their contexts.
To suppress chunks where terms are not present, use Only if Term Present (Term-Doc) instead.