TABLE 1.

The table shows the results of the frustration scales of the NASA-TLX and the EaCQ (see also section “Frustration can be determined with subjective methods”).

Time point	Factors	Upper bound	Lower bound	Effect size	p-value
After first interaction	Frustration (EaCQ 1)	0.04	1.68	0.383	0.04
	Frustration (NASA 1)	14.84	49.52	0.616	0.001
After second interaction	Frustration (EaCQ 2)	0.43	1.76	0.541	0.002
	Frustration (NASA 2)	16.48	48	0.661	0.0003