Abstract: Progressively smaller pieces can be connected to the largest piece to aid in semantic mapping of an informative passage, for example. Legends can be applied to the pieces (and can be wiped off later). The pieces can be connected mechanically or magnetically. The mechanical connections can be different shapes to limit connection of a piece to the next larger piece. Similarly, the pieces can be magnetized to achieve the same end. The perimeter of each piece can be color coded to indicate the color of the proper piece to be connected to the perimeter.