Color versus shape coding in information displays

8 Ss counted objects of a specified color or shape on displays of 20, 60, or 100 items. Counting time and errors increased with increasing display density. Counting based on a 5-valued color code was faster and more accurate than counting using any of 3 shape codes. Color counting was not affected by the particular shape code on which the colors were superimposed. Shape counting was somewhat faster and/or more accurate when color did not vary on the display, and vice versa. Differences in counting performance appeared among the 3 shape codes and among certain of the symbols within shape codes, and small differences were confirmed among the particular code colors used.