  With the uptake of algorithmic personalization in the news domain, news
organizations increasingly trust automated systems with previously considered
editorial responsibilities, e.g., prioritizing news to readers. In this paper
we study an automated news recommender system in the context of a news
organization's editorial values. We conduct and present two online studies with
a news recommender system, which span one and a half months and involve over
1,200 users. In our first study we explore how our news recommender steers
reading behavior in the context of editorial values such as serendipity,
dynamism, diversity, and coverage. Next, we present an intervention study where
we extend our news recommender to steer our readers to more dynamic reading
behavior. We find that (i) our recommender system yields more diverse reading
behavior and yields a higher coverage of articles compared to non-personalized
editorial rankings, and (ii) we can successfully incorporate dynamism in our
recommender system as a re-ranking method, effectively steering our readers to
more dynamic articles without hurting our recommender system's accuracy.
