On the Decaying Utility of News Recommendation Models

For how long will a recommendation model provide adequate recommendations? The answer to this question depends on the kind of model, its underlying data, and the domain among other factors. We analyse four types of models in the news domain on how their predictive performances change. Our observations show that replacing or updating models is necessary to maintain high predictive performance. The evaluation suggests that an exponential decay model describes the changing predictive performance accurately.