The ability to recognize distortions of, for example, areas, angles, and landmass shapes in global-scale map projections, is an important part of critical map reading and use. This study investigates the cues used by individuals when they assess distortion on global-scale map projections. It was hypothesized that landmass shape would be a dominant cue used by individuals with no formal map projection training and that as projection knowledge increased the cues would become more systematic (e.g., use the graticule). Results indicate a tendency for novices to rely on landmass shape as a cue. Some evidence of a systematic evaluation of projections was also found. (Contains 7 figures and 5 tables.)