While Wikipedia is an excellent source of information about entities, discovering relationships among them is not well-supported by its search features. Lensing Wikipedia was designed as an alternate search and summarization interface, providing a set of filtering, visualization, and exploration tools that enable searching among the connections between people, organizations, and locations. In this paper, we present the results of a user study on how these features are used in each of Vakkari's stages of information seeking (pre-focus, focus formulation, and post-focus), and the participants perceptions of the utility of these features to their overall information-seeking goals. Participants primarily used input and control features during the pre-focus stage, informational and personalization features during the focus formulation stage, and personalization features during the post-focus stage. Findings from this study contribute to understanding how people use advanced search, summarization, and visualization tools to aid their information seeking tasks.