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J M Flach

Publications and source records attributed to J M Flach.

6 recordsLinked to original sources
PubMed1992

The complex role of perceptual organization in visual display design theory.

Two experiments were performed to test and extend the current 'emergent features' approach to display design for dynamic failure detection tasks. It was predicted that a display whose emergent features were well-mapped to goal-relevant task invariants would lead to better failure detection performance than either of two alternative displays. Contrary to prediction. Experiment 1 showed no differences in failure detection speed or accuracy across displays. The reason for this may have been that subjects did not discover the mapping between the mathematical properties of the task and the emergent feature, so in Experiment 2 subjects were explicitly instructed about the mapping and were advised on how to use the display geometry to help their performance. A significant difference in failure detection speed emerged, but the display supporting fastest performance was not the one with the well-mapped emergent feature. These results suggest that alternative perceptual organizational factors were at work which overpowered the intended effect. The results also underscore the difficulty of developing a theory of display design, and their impact on current theories is outlined.

Adult↗
PubMed1992

Graphical displays: implications for divided attention, focused attention, and problem solving.

When completing tasks in complex, dynamic domains observers must consider the relationships among many variables (e.g., integrated tasks) as well as the values of individual variables (e.g., focused tasks). A critical issue in display design is whether or not a single display format can achieve the dual design goals of supporting performance at both types of tasks. We consider this issue from a variety of perspectives. One relevant perspective is the basic research on attention and object perception, which concentrates on the interaction between visual features and processing capabilities. The principles of configurality are discussed, with the conclusion that they support the possibility of achieving the dual design goals. These considerations are necessary but not sufficient for effective display design. Graphic displays map information from a domain into visual features; the tasks to be completed are defined in terms of the domain, not in terms of the visual features alone. The implications of this subtle but extremely important difference are discussed. The laboratory research investigating alternative display formats is reviewed. Much like the attention literature, the results do not rule out the possibility that the dual design goals can be achieved.

Attention↗
PubMed1992

Active regulation of altitude as a function of optical texture.

Two empirical studies are reported that examine active regulation of altitude as a function of the type of ground texture. Three ground textures were examined: lines perpendicular to the direction of motion, lines parallel to the direction of motion, and the combination (i.e., square or checkerboard texture). Although subjects only controlled altitude, disturbances were introduced on three axes: vertical, lateral, and fore-aft. The results show a clear advantage for texture parallel to the direction of motion. However, in considering these results in the context of previous research on altitude control, the argument is made that there is no compelling evidence that suggests either parallel (splay) or perpendicular (density) texture is privileged with regard to altitude control. Rather, the most effective display for altitude control will be the one that best isolates the optical activity associated with changing altitude from the optical activity arising from other sources of disturbance (such as forward locomotion). Such a display will make it easier for the observer to distinguish and respond specifically to the disturbances of altitude.

Adult↗
PubMed1990

Sources of optical information useful for perception of speed of rectilinear self-motion.

Magnitude judgments of the speed of self-motion were examined. The principal independent variables were edge rate, global optical flow rate, and the type of texture (grid or dot). Results indicated that edge rate and global optical flow rate had additive effects on magnitude judgments, with edge rate accounting for a larger portion of the variance. Effects were independent of texture type. Secondary variables examined were viewing condition and task load. Attempts were made to control the availability of flatness cues. Evidence indicates that the effectiveness of global optical flow rate varied with the control of flatness cues. A secondary running auditory Sternberg task was used to prevent edge counting; the presence of this task did not reduce the effect of edge rate. These results replicate and extend previous work by D. H. Owen and colleagues.

Acceleration↗