Table 2.

Z-statistics (P values) for Wilcoxon signed rank test for pairs of session averages of involved and uninvolved treatments in the English auction

	Round 1	Round 2	Rounds 1 and 2 pooled
Single and 30	2.10	1.12	2.17
pooled	(.036)	(.263)	(.030)
	8 pairs	8 pairs	16 pairs
Single only	1.75	1.60	2.10
	(.080)	(.109)	(.036)
	5 pairs	3 pairs	8 pairs
30 only	1.60	−.135	.98
	(.109)	(.893)	(.327)
	3 pairs	5 pairs	8 pairs