Table 1.

Successive Matching Training Contingencies for the Two Groups

Hue-Form (AB) Matching	Hue-Hue (AA) Oddity	Form-Form (BB) Identity
Group HO
R → T - FI 5 s	R → R - EXT	T → T - FI 5 s
R → H - EXT	R → G - FI 5 s	T → H - EXT
G → T - EXT	G → R - FI 5 s	H → T - EXT
G → H - FI 5 s	G → G - EXT	H → H - FI 5 s
Hue-Form (AB) Matching	Hue-Hue (AA) Identity	Form-Form (BB) Oddity
Group FO
R → T - FI 5 s	R → R - FI 5 s	T → T - EXT
R → H - EXT	R → G - EXT	T → H - FI 5 s
G → T - EXT	G → R - EXT	H → T - FI 5 s
G → H - FI 5 s	G → G - FI 5 s	H → H - EXT

Note. R = red, G = green, T = triangle, H = horizontal lines, FI = fixed interval schedule, EXT = nonreinforced. The first stimulus in the trial sequence (the sample) is shown to the left of the arrows, and the second stimulus (the comparison) is shown to the right. Counterbalancing of the hue–form matching contingencies has been omitted.