Error Keys As Reference Aids In Image Interpretation

The Surveillance Systems Project is directed toward increasing knowledge related to the techniques and procedures for interpreting aerial imagery and reducing extracted information to its most usable form. One Task, specifically concerned with image interpretation displays, conducts research to develop improved reference materials to assist image interpreters in locating and correctly identifying objects of military significance in aerial photographs. Specially developed reference keys are tested in controlled studies with interpreter output measures as criteria. The present publication describes one of the first such studies. An 'error key', developed through analysis of interpreter errors and designed to help interpreters avoid common misidentifications, and a 'rights key' similar to keys currently used by image interpreters, were provided to accompany two sets of aerial imagery. Two performance measures based on this imagery were administered to three matched groups of interpreter trainees. One group used the 'error key', another group used the 'rights key', and a control group used no reference key. Performance data for the three groups--correct identifications, errors, and interpreters' confidence in their identifications--were analyzed. The 'error keys' resulted in substantial decrease in errors and increase in accuracy, but no difference in number of correct identifications. They also affected the differential between interpreters' confidence in right and wrong identifications, increasing the amount of difference in one performance measure, and decreasing the amount in the other. The 'rights key' did not have a significant effect on any aspect of performance measured.