A successful collaborative tool designed to aid discussion must be flexible, maintain the user’s coordinative agency, and be appropriable in many contexts. We have developed a tool, called ThoughtSwap, to help widen and deepen the scope of participation in facilitated discussions while supporting, not supplanting, discussants’ coordination. By driving the design of ThoughtSwap toward a simpler mechanism, we were able to create a more versatile, high-impact tool. We design for an educational setting, but see wider possible use. Author Keywords CSCW, CSCL, coordinative agency, collocated discussion, classroom discussion ACM Classification Keywords H.5.3 [Group and Organization Interfaces]: Computersupported cooperative work General Terms Experimentation, Human Factors