Most students will be familiar with the compass as a tool that points north. However, the compass only shows us one component—the terrestrial projection—of the Earth’s magnetic field. In contrast, the IOLab potentially gives students access to the actual direction of the field. We have designed an open-ended task in which pairs of students use the IOLab to determine the actual direction of the Earth’s magnetic field in a laboratory classroom. Without any prior instruction or step-by-step procedure to follow, students simultaneously coordinate a set of resources: speech (in groups; and with facilitator), interpretation of graphical readouts, physical manipulation of the IOLab and proprioception. By coordinating the resources available, the students in our study can be seen to quickly come to a moment of disciplinary insight, where they realize the true direction of the magnetic field.