Three matching-to-sample experiments examined whether spatial or configural factors determined how the element arrangement of compound sample stimuli influenced matehing accuracy in pigeons. Seven types of compound stimuli were tested. The arrangement of color and lineorientation elements in these compounds varied in terms of the spatial separation between the elements, the degree ofconsistency in element spatiallocation, and the number ofbounded areas containing the elements. Matching accuracy was examined upon initial exposure to the compounds, during asymptotic conditions of shared attention, and with variation of sample durations ranging from .04 to 5.935 sec. In all three experiments, when spatial proximity, locational certainty, and the number of lines were precisely controlled or equated, no evidence for the proposed configural processing of"unified" compounds was found (Lamb & Riley, 1981). Element spatial separation, and to a lesser degree perceptuallimitations, determined compound performance. These results question our lab's previous evidence for configural compound processing by pigeons (Lamb, 1988; Lamb & Riley, 1981).They suggest instead that pigeons independently and separately process the individual elements of color/line-orientation compounds, with element separation determining the distribution of processing between the elements.Research on humans has shown that the organization of the elements fonning a compound visual stimulus strongly influences its psychological properties (Ceraso, 1985; Gamer, 1974 Gamer, , 1976. Riley and Leith (1976) similarly proposed that element organization may also influence how pigeons process compound stimuli. Since then, two reports from our lab (Lamb, 1988; Lamb & Riley, 1981) have offered evidence in support of this proposal, obtained in variations of the element/compound delayed matchingto-sample (E/C DMTS) task.In the E/C DMTS task, the pigeon is presented with either an element sample, consisting of one of two color elements (red or green, henceforth R or G) or one oftwo line-orientation elements (vertical or horizontal, henceforth V or H), or a compound sample, consisting ofboth acolor and a lineelement (RH, RV, GH, GV). The sample is followed by a test in which the two values of a single dimension are pitted against one another (R vs. Gor