Computers designed for single use are often appropriated suboptimally when used by small colocated groups working together. Our research investigates whether shareable interfaces-that are designed for more than one user to interact with-can facilitate more equitable participation in colocated group settings compared with single user displays. We present a conceptual framework that characterizes Shared Information Spaces (SISs) in terms of how they constrain and invite participation using different entry points. An experiment was conducted that compared three different SISs: a physical-digital set-up (least constrained), a multitouch tabletop (medium), and a laptop display (most constrained). Statistical analyses showed there to be little difference in participation levels between the three conditions other than a predictable lack of equity of control over the interface in the laptop condition. However, detailed qualitative analyses revealed more equitable participation took place in the physical-digital condition in terms of verbal utterances over time. Those who spoke the least contributed most to the physical design task. The findings are discussed in relation to the conceptual framework and, more generally, in terms of how to select, design, and combine different display technologies to support collaborative activities.