Three-Dimensional Map Construction

Naïve realism: folk fallacies in the design and use of visual displays

Often implicit in visual display design and development is a gold standard of photorealism. By approximating direct perception, photorealism appeals to users and designers by being both attractive and apparently effortless. The vexing result from numerous performance evaluations, though, is that increasing realism often impairs performance. Smallman and St. John (2005) labeled misplaced faith in realistic information display Naïve Realism and theorized it resulted from a triplet of folk fallacies about perception. Here, we illustrate issues associated with the wider trend towards realism by focusing on a specific current trend for high-fidelity perspective view (3D) geospatial displays. In two experiments, we validated Naïve Realism for different terrain understanding tasks, explored whether certain individuals are particularly prone to Naïve Realism, and determined the ability of task feedback to mitigate Naïve Realism. Performance was measured for laying and judging a concealed route across realistic terrain shown in different display formats. Task feedback was either implicit, in Experiment 1, or explicit in Experiment 2. Prospective and retrospective intuitions about the best display formats for the tasks were recorded and then related to task performance and participant spatial ability. Participants generally intuited they would perform tasks better with more realism than they actually required. For example, counter to intuitions, lowering fidelity of the terrain display revealed the gross scene layout needed to lay a well-concealed route. Individuals of high spatial ability calibrated their intuitions with only implicit task feedback, whereas those of low spatial ability required salient, explicit feedback to calibrate their intuitions about display realism. Results are discussed in the wider context of applying perceptual science to display design, and combating folk fallacies.

Inhibitory fields in the Limulus lateral eye

The inhibition that is exerted mutually among receptor units (ommatidia) of the lateral eye of Limulus does not diminish uniformly with increasing distance between units. Instead the response of a receptor unit is most effectively inhibited by other units separated from it by approximately 1 mm (three to five receptor diameters); the effectiveness diminishes with distances both greater and less than this value. The ommatidial inhibitory field as measured by the spatial function of the inhibitory coefficients contains a uniform depression in the central region, a uniformly high annulus at some distance from the center, and a gradual tapering off toward the periphery. The field is large-covering over 30 % of the retina-and is somewhat elliptical in shape with its major axis in the anteroposterior direction on the lateral eye. A number of experiments reveal similar configurations in a sizable part of the eye. Control experiments show that the diminution of the inhibitory effects near the center of the field is not an artifact of the measuring technique and cannot be explained readily by local neural excitatory processes.