Among the false negatives we analyzed, we found that the model is most likely to miss "tricky" quotations that are unusual in their grammatical structure.
it tends to miss a class of quotations that are expressed as short noun phrases or adjectival phrases embedded within a non-quotation sentence such as According to the PARC guidelines, these are cases of quotations since they are attributable statements, but they are difficult for the model to retrieve since they are hard to distinguish from "non-quotation" nominal phrases -in particular in cases like this one, where there are not even overly realized speakers.