Table 1.

Item response model parameter estimates (Study 1).

i	${\mathit{x}}_{\mathbf{i}}^{(\mathbf{j})}$	B i	SE(Bi)	β i	SE(βi)	c i	SE(ci)	p
0	Intercept	−8.388	0.983	NA	NA	−8.388	0.983	< 0.001
1	Beep-track accuracy	10.025	1.282	0.902	0.115	10.025	1.282	< 0.001

Notes. i is a generic index. ${\mathrm{x}}_i^{(j)}$ denotes the ith element of vector x^(j) (equation (3)), and corresponds to the ith item feature. B_i denotes an unstandardised regression coefficient. SE(B_i) denotes the standard error associated with the estimation of B_i, and analogous definitions hold for SE(β_i) and SE(c_i). β_i denotes a fully standardised regression coefficient. c_i denotes the ith element of vector c (equation 3), and identifies the contribution that item feature $x_i^{(j)}$ makes to item difficulty.