We noticed that when the review number of a user or a product reaches some point (|N u (r)| = 3 − 7 in the Blitzer dataset and |N p (r)| = 2 − 5 in the Maas dataset), having more reviews does not improve the accuracy any further.
higher |N u (r)| or |N p (r)| number induces lower speed of easiest-first decoding as we analyzed in Section 3.4.