VISUAL SEARCH FOR TARGETS: LABORATORY EXPERIMENTS,

In laboratory experiments conducted at NOTS, visual search performance of 16 male subjects was measured and related to display- and observerdependent parameters. Several facts emerged a significant correlation exists between peripheral visual acuity scores and search-time scores for a search task in a static field. This correlation is dependent upon the angle of the visual axis at which acuity is measured and the number of objects in the field being searched. When the field is moving with respect to the subject, search performance decreases when the velocity of the field increases. Comparison of data from the static search experiment with that from the dynamic experiment indicates that this perfomance degradation is due to a time limitation and not to motion per se. Further, with velocity increase, foveal acuity becomes more important than peripheral acuity in the search task. Search time is proportional to the number of objects in the display, and introduction of a linear cue into the display greatly decreases search time. Author