The recent advances in mobile technologies and their increasing
popularity are speeding up the achievement of the ubiquitous computing vision [1]. For the first time ever there are more gadgets in the world
than there are people [2]. Smartphone sales surpassed one billion units
in 2014 [3] and it is expected that over half of mobile phone users globally will have smartphones in 2018 [4]. In addition to this, global mobile
data traffic grew 69% in 2014 [5]. It is a fact that these devices are replacing cameras, music players and Global Positioning System (GPS) tools.
Definitely, they have become an open window to information and services at any time and place. This computing scenario requires the development of new technologies in order to provide mobile users with the
correct information and services on the move. This way, a personalization layer is needed in order to filter and adapt all the information
that is consumed by mobile users