Table 4. Model selection for back-off speed using information criteria AIC, BIC, and p-value between model (5) and the models (1)–(4).

No.	Modela	AIC	BIC	p
(1)	BO.speed ∼ robot.length + viewpoint, 1|participant	156.1905	177.2636	< 0.001
(2)	BO.speed ∼ robot.length * viewpoint, 1|participant	157.5327	182.8203	< 0.001
(3)	BO.speed ∼ robot.length + viewpoint, 1|participant.height	441.2020	462.2750	< 0.001
(4)	BO.speed ∼ robot.length + viewpoint, viewpoint|participant	160.1905	189.6928	-
(5)	BO.speed ∼ robot.length + viewpoint, robot.length|participant	-29.22402	0.27823

^aNotation used is in R-format.