Table 5.

Generalised linear model on the proportion of times the dogs’ chose S’ when paired with the known negative (test 1 refresher) and also chose S’ in the subsequent trial when S’ was paired with the novel S” (test 2 trial) in the inference by exclusion task, showing the direction of effects and the significance level of the terms

Response variable	Model	Minimal model	Average effect	SE	Wald statistic /deviance	z	p value
Proportion of times chose S’ in both test 1 refresher trial and test 2 trial	Model 12	Age in months	0.0099	0.0014	45.538		<0.001
		Stimulus: group B	0.7027	0.1367	27.739		<0.001
	Model 13	Age group			54.570		<0.001
		Age group 2	0.4654	0.2816		1.653	0.094
		Age group 3	0.6387	0.2989		2.137	0.033
		Age group 4	1.2223	0.2900		4.215	<0.001
		Age group 5	1.3916	0.2788		4.992	<0.001
	Model 14	Sessions to criterion	0.0008	0.0029	0.082		0.775
	Model 15	Total no. of correction trials	0.0006	0.0003	4.103		0.043

Z tests indicate which age groups differ from age group 1 in the respective analysis. Age in months was included in models 12 and 13 to control for age effects. Bold numbers indicate significant values at p = ≤0.05