Luz, NunoAnacleto, RicardoMartins, ConstantinoAlmeida, Ana2013-04-292013-04-29201110.1007/978-3-642-19917-2_10978-3-642-19916-5978-3-642-19917-21867-5662http://hdl.handle.net/10400.22/1472In the context of previous publications, we propose a new lightweight UM process, intended to work as a tourism recommender system in a commercial environment. The new process tackles issues like cold start, gray sheep and over specialization through a rich user model and the application of a gradual forgetting function to the collected user action history. Also, significant performance improvements were achieved regarding the previously proposed UM process.engUser modelingTourismRecommendationbook part2013-04-21