Figure 7: The effect of time. We show the unique semantic categories mentioned in the citances from the same publication year as the original target paper and how they overlap with the semantic categories matched in the target abstracts. Semantic annotations and overlap with the abstract for the following 1, 2, 3, and 4+ years are also shown. Note that only new unique semantic annotations are counted, for example, annotations of “citances of year 2” do not include any annotations that already appeared in years 0 or 1.