Table A2.

Experiment 3. Mean criterion and positional noise, in units of blur (B, 8 min arc), derived directly from the control data (Figure 11) without modelling

Polarity:	Same			Opposite
Observer	criterion	noise	c/n ratio	criterion	noise	c/n ratio
SAW	0.84	0.26	3.21	0.82	0.34	2.43
DHB	0.77	0.46	1.69	0.84	0.52	1.63
ASB	0.38	0.57	0.66	0.35	0.73	0.48
RH	0.67	0.58	1.16	0.67	0.63	1.06
Group mean	0.66	0.46	1.68	0.67	0.55	1.40