This paper describes the design rationale and the results of a preliminary evaluation of "XingBoard", a tablet-based tool that supports a bi-directional transition between personal work and collective activities in the learning process. For this purpose, this system provides a shared space for discussion comprised of multiple, connected tablet terminals and allows users to move post-it like idea cards from one terminal to another. In addition, the system can copy cards from a shared space (i.e, connected tablets) to each learner's tablet for personal work, which consists of reflection on revision of the result of the discussion. The preliminary evaluation shows that this tool is easy to use and aids the transition between the two modes of activity: personal and collective.