“…• activity: all the activities related to the information need, ranging from those that generated the information need to those that will be pursued on the basis of the retrieved information (this component deserves some further explanations, see below); • preferences: user's preferences related to the topic or the activity considered (e.g., Rashid et al, 2002); • social: the social context that can influence the relevance of an entity, such as the popularity within a community or among user's connections (e.g., Mizzaro and Vassena, 2011); • mobility: the spatio-temporal availability of the entity (e.g., location and opening hours), the spatiotemporal situation of the user (e.g., location, time schedule, and mode of transportation), available mobility infrastructure, and topological structure (e.g., Mountain and MacFarlane, 2007); • context: everything not pertaining to the previous components, including knowledge about the physical surroundings (e.g., light level or other geographic entities in the surroundings) and informational surroundings (e.g., information contextual to the topic or activity).…”