Target detection in scientific visualization

Three experiments were conducted to test participants' ability to detect ta rgets in colored spatial displays using 7-level bipolar scales. Experiment 1 assessed the ability of participants to detect high or low targets using 12 scales whose poles either were directly opposed in color space or had a primary and an intermediate hue at each pole. Experiment 2 used 8 scales wh ose arms were orthogonal in color space. Experiment 3 examined the simultan eous detection of high and low targets. Although there are notable exceptio ns, scales that are close to or above the horizontal (red-green) axis in co lor space perform best. Of the scales with orthogonal arms, those that are oriented downward, toward the blues, in color space are least satisfactory. Scales that are asymmetrically effective are common, and applications requ iring good detectability at both extremes must take this into account. The results are discussed in the context of the evolution of trichromatic color vision.