Streaming Submodular Maximization with Fairness Constraints

We study the problem of extracting a small subset of representative items from a large data stream. Following the convention in many data mining and machine learning applications such as data summarization, recommender systems, and social network analysis, the problem is formulated as maximizing a monotone submodular function subject to a cardinality constraint -- i.e., the size of the selected subset is restricted to be smaller than or equal to an input integer $k$. In this paper, we consider the problem with additional \emph{fairness constraints}, which takes into account the group membership of data items and limits the number of items selected from each group to a given number. We propose efficient algorithms for this fairness-aware variant of the streaming submodular maximization problem. In particular, we first provide a $(\frac{1}{2}-\varepsilon)$-approximation algorithm that requires $O(\frac{1}{\varepsilon} \cdot \log \frac{k}{\varepsilon})$ passes over the stream for any constant $ \varepsilon>0 $. In addition, we design a single-pass streaming algorithm that has the same $(\frac{1}{2}-\varepsilon)$ approximation ratio when unlimited buffer size and post-processing time is permitted.