Table 2. Mean Parameter Values and SD's Across Subjects for the Lexical Decision Experiment.

	Trial group	a	Ter	η	sz	p0	st	z	vH	vL	vV	vN	χ2
Mean	1-120	0.153	0.476	0.133	0.038	0.001	0.171	0.081	0.660	0.271	0.159	-0.240	43.0
	121-240	0.162	0.462	0.150	0.042	0.002	0.175	0.085	0.626	0.323	0.186	-0.259	41.2
	241-360	0.153	0.457	0.122	0.062	0.003	0.153	0.081	0.618	0.290	0.165	-0.233	36.7
	1-240	0.148	0.471	0.139	0.040	0.003	0.182	0.075	0.581	0.272	0.147	-0.219	63.3
	241-480	0.144	0.454	0.125	0.051	0.002	0.173	0.083	0.516	0.244	0.135	-0.204	61.0
	1-480	0.143	0.458	0.132	0.045	0.001	0.193	0.083	0.502	0.237	0.122	-0.201	82.3
	481-960	0.138	0.445	0.144	0.054	0.002	0.167	0.076	0.431	0.206	0.104	-0.221	83.2
	1-2100	0.135	0.436	0.123	0.066	0.002	0.178	0.080	0.399	0.203	0.114	-0.216	158.
SD	1-120	0.041	0.062	0.052	0.037	0.003	0.078	0.028	0.185	0.113	0.087	0.092	20.7
	121-240	0.054	0.052	0.057	0.039	0.006	0.084	0.040	0.176	0.150	0.114	0.100	18.2
	241-360	0.035	0.044	0.045	0.039	0.009	0.084	0.039	0.176	0.136	0.122	0.068	14.0
	1-240	0.040	0.055	0.055	0.036	0.011	0.070	0.028	0.175	0.101	0.077	0.073	20.4
	241-480	0.037	0.040	0.048	0.040	0.005	0.071	0.027	0.164	0.099	0.080	0.055	24.1
	1-480	0.033	0.040	0.047	0.033	0.001	0.059	0.028	0.141	0.087	0.070	0.047	26.1
	481-960	0.030	0.033	0.049	0.030	0.006	0.062	0.024	0.106	0.078	0.069	0.052	25.0
	1-2100	0.025	0.029	0.036	0.025	0.003	0.049	0.023	0.096	0.063	0.052	0.041	51.5
Mean	Simulation parameters	0.14	0.44	0.115	0.04		0.17	0.080	0.38	0.19	0.11	-0.20
SD		0.04	0.04	0.06	0.02		0.06	0.002	0.06	0.06	0.06	0.06

Note. a=boundary separation, z=starting point, T_er=nondecision component of response time, η =standard deviation in drift across trials, s_z=range of the distribution of starting point (z), s_t = range of the distribution of nondecision times, v_H, v_L, v_V, and v_N are the drift rates for high, low, and very low frequency words and for nonwords respectively, and χ² is the chi-square goodness of fit measure. The number of degrees of freedom for the fits to data was 65 and the critical value of chi-square at the .05 level was 84.8. In the simulations, the drift rates were not correlated. The following were lower limits on parameter values: a, 0.07; η, 0.02; T_er, 0.25; s_t, 0.04, s_z, 1.8 the distance from the starting point to the nearest boundary. Separate sets of simulations were conducted with p_o 0 or 0.04. Each drift rate had the same random number added to it so if a subject had a high drift rate in one condition they had a high drift rate in the other conditions.