A method for estimating the quality of experience of a service provided over a communication network from activities performed by a user in the fruition of said service through a user device (12a, 12b, 12c) connected to said communication network, the method comprising, at a processing unit connected to said communication network: a1) detecting a data traffic within said communication network comprising events indicative of said activities performed by the user in the fruition of said service during a user session; a) subdividing said user session of the service into a number of time intervals; b) determining a number of said events indicative of said activities performed by the user during a time interval, T x, of said number of time intervals; and c) on the basis of said events, calculating an index, BT x, indicative of the quality of experience of said service in said time interval, wherein the method further comprises, at step b): b1) subdividing said time interval, T x, into a number of time sub-intervals; b2) gathering a number of elementary events, each elementary event being indicative of a respective activity performed by the user during a time sub-interval, t i,x, of said number of time sub-intervals; and b3) combining said elementary events into a complex event and comparing said complex event with a set of patterns, each pattern being associated with a respective predefined combination of elementary events and with a predefined index, B i,x, indicative of the quality of experience associated with said predefined combination of elementary events. a1) detecting a data traffic within said communication network comprising events indicative of said activities performed by the user in the fruition of said service during a user session; a) subdividing said user session of the service into a number of time intervals; b) determining a number of said events indicative of said activities performed by the user during a time interval, T x, of said number of time intervals; and c) on the basis of said events, calculating an index, BT x, indicative of the quality of experience of said service in said time interval, a) subdividing said user session of the service into a number of time intervals; b) determining a number of said events indicative of said activities performed by the user during a time interval, T x, of said number of time intervals; and c) on the basis of said events, calculating an index, BT x, indicative of the quality of experience of said service in said time interval, wherein the method further comprises, at step b): b1) subdividing said time interval, T x, into a number of time sub-intervals; b2) gathering a number of elementary events, each elementary event being indicative of a respective activity performed by the user during a time sub-interval, t i,x, of said number of time sub-intervals; and b3) combining said elementary events into a complex event and comparing said complex event with a set of patterns, each pattern being associated with a respective predefined combination of elementary events and with a predefined index, B i,x, indicative of the quality of experience associated with said predefined combination of elementary events. b1) subdividing said time interval, T x, into a number of time sub-intervals; b2) gathering a number of elementary events, each elementary event being indicative of a respective activity performed by the user during a time sub-interval, t i,x, of said number of time sub-intervals; and b3) combining said elementary events into a complex event and comparing said complex event with a set of patterns, each pattern being associated with a respective predefined combination of elementary events and with a predefined index, B i,x, indicative of the quality of experience associated with said predefined combination of elementary events.