“…in a CF based website) in such a way that when enough information is stored on the system, we can make recommendations to each user based on information provided by those users we consider to have the most in common with them. CF is an interesting open research field (Xie, Han, Yang, Shen, Zeng, & Chen, 2007;Bobadilla, Hernando, Ortega, & Bernal, 2011;Bobadilla, Hernando, Ortega, & Gutiérrez, 2012). As noted earlier, user ratings can also be implicitly acquired (e.g., number of times a song is heard, information consulted and access to a resource).…”