Visual search experiments inherently require numerous repetitions and/or a large number of observers to obtain statistically significant data. In field experiments it is usually impossible to perform the same scenario more than once, simply because one has no control over the environmental conditions. In addition, field trials are usually extremely elaborate and often very costly or even dangerous. But even in the laboratory, where one has in principle complete control over all experimental parameters, search experiments are very time consuming because they involve a large number of observations. It is therefore of great practical value to have a visual target characteristic 1) that reliably predicts human visual search performance and 2) that can easily and quickly be determined in situ, with only a few observers. Visual target conspicuity has this potential. Visual conspicuity refers to the discrepancy between the visual signatures of a target and its local background. This discrepancy can arise from differences in size, shape, luminance, color, texture, binocular disparity, and motion. A target’s local feature contrast should exceed the overall variation of the background to make it stand out and attract the observer’s attention. Note that an object is not conspicuous per se; it is only conspicuous when it is sufficiently different from its surroundings.