Table 1. Dataset statistics.

Dataset	#Data	#User	#Item	#User attr.	#Item attr.
MovieLens 1M	1,149,238	5,950	3,514	30	6,944
Book-crossing	1,050,834	4,873	53,168	87	43,157
Taobao	2,599,463	4,532	371,760	36	434,254