To the right you will find an interactive example of compound samples (shape + color) and shape tests used by Langely and Riley (1993). The sample is either a triangle or a circle (as in the element shape tests) but it is colored either blue or green. The pigeon’s task is to respond based only on shape and not color. Consequently, the comparisons that were associated with the shape samples in the element matching phase are presented here. You will notice that the compound samples in these tests are identical to the compound samples in the color tests. The relevant information in the sample (color or shape) is only known once the comparisons are presented.

To run the applet…

• Peck the white ready signal on the center key
• Now the sample is presented. It is a triangle or circle colored either blue or green. Peck it once.
• You will recognize the comparisons as those presented after shape samples in the element task. One comparison is correct following a triangle (whether blue or green) and the other is correct following a circle (whether blue or green). A correct choice results in a food reward (the hopper box turns yellow), and an incorrect choice results in a time out (the intertrial interval)
• After the ITI, the ready signal appears again and a new trial is ready to begin.