This article in the Journal of Geoscience Education describes a classroom exercise based on four world maps containing earthquake, volcano, topographical and seafloor age data. Students participate in this exercise by using a "jigsaw" approach, in which they break into four groups and become specialists on one of the map types. After being organized into new groups with one specialist from each map represented, the groups present their data from the class. The exercise takes three 50 minute class periods to complete and involves the students making presentations to one another in small groups and to the whole class. The exercise is useful at a wide variety of levels because it is based only on observation and description. This exercise (assessment tool) has shown that students come away with knowledge of the key features of each type of plate boundary and a sense of why it looks the way it does.