Mixing and matching lower-level codes for object displays: Evidence for two sources of proximity compatibility

The proximity compatibility principle (PCP) proposes that visually unitary configurations of data values, such as object displays, will support information integration better than will more separable formats. In the present study formats were created by either mixing or matching pairs of lower-level codes (i.e., linear extent, angle, and color). Performance with object and separable configurations of these codes was compared for two integration tasks: system state classifications requiring either (1) comparisons of values or (2) identification of conjunctions of values. Object displays formed with matched codes were more likely to facilitate comparisons, whereas object displays formed from mixed codes were more likely to facilitate conjunction identification. These data suggest that two mechanisms may underlie object display advantages for integration-one based on relational properties or emergent features and one based on the efficient processing of the lower-level codes themselves.