Table 7.

Model estimates for the probabilities of the cues used for target recognition. The values were derived from confusion matrices, combining across the four groups, using the probabilistic model described in the text. The first row of values shows cue probabilities based on data combined across all conditions. The second section shows cue probabilities for the three light sources. The third section shows values for the three viewing distances. Probabilities for the Transition Contrast and Kink cues for Step Up are always equal for reasons discussed in Appendix 1.

		Transition Contrast P1	Kink P2	L-Junction P3	Bend In/Out P4	Picture Plane P5
Overall		.70	.70	.72	.29	.60
Lighting	Overhead	.71	.71	.66	.28	.61
	Far Window	.81	.81	.74	.48	.51
	Near Window	.61	.61	.77	.03	.68
Distance	5ft	.76	.76	.85	.14	.64
	10ft	.86	.86	.76	.39	.60
	20ft	.56	.56	.56	.31	.57