Table 2.

Wh-islands model summary: usage by grammaticality.

Parametric coefficients	β	SE	t	p
(Intercept)	0.0002	0.0035	0.07	0.94
Smooth terms	EDF	Ref.DF	f	p
s(Sample)	3.88	4.63	5.36	<0.001	*
s(Sample): IsUngram	1.00	1.01	0.36	0.55
s(Historical Usage)	1.00	1.00	1.52	0.22
s(Historical Usage): IsUngram	1.01	1.01	1.87	0.09
s(Current Usage)	1.40	1.46	1.99	0.10
s(Current Usage): IsUngram	3.79	4.26	7.88	<0.001	*
ti(Sample, Historical Usage)	1.01	1.02	1.18	0.28
ti(Sample, Historical Usage): IsUngram	2.32	2.79	1.06	0.27
ti(Sample, Current Usage)	2.04	2.19	2.93	0.05
ti(Sample, Current Usage): IsUngram	4.35	5.80	4.20	<0.001	*
s(X Gaze, Y Gaze)	37.73	38.90	122.36	<0.001	*
s(Sample, Subject)	159.47	387.00	1.43	<0.001	*
s(Sample, Item)	65.15	299.00	0.38	<0.001	*

*p < 0.05.