In contrast to Doc-Pred, Sent-Pred can find regularities at the sub-document level, and generate partial responses, which typically omit inappropriate sentences that may be included by Doc-Pred.
the responses generated by Sent-Pred have a consistently high precision (average 0.94, standard deviation 0.13), but this can be at the expense of recall, which explains the lower F-score (compared to Doc-Pred).