CLEF 2017 NewsREEL Overview: Offline and Online Evaluation of Stream-based News Recommender Systems.

The CLEF NewsREEL challenge allows researchers to evaluate newsrecommendation algorithms both online (NewsREEL Live) and offline (News-REEL Replay). Compared with the previous year NewsREEL challenged participantswith a higher volume of messages and new news portals. In the 2017edition of the CLEF NewsREEL challenge a wide variety of new approaches havebeen implemented ranging from the use of existing machine learning frameworks,to ensemble methods to the use of deep neural networks. This paper gives anoverview over the implemented approaches and discusses the evaluation results.In addition, the main results of Living Lab and the Replay task are explained.