Table 2.

Properties of the VIENNA items

Item	Item type	$\frac{\overline{M}}{E}$	$\overline{M}$	$E$	0	1	2	$s^2$	$e$
i1	No-turn	3.94	1.97	0.50	0	2	77	0.02	0.19
i2	No-turn	5.42	1.95	0.36	0	4	75	0.05	0.57
i3	No-turn	9.38	1.97	0.21	1	0	78	0.05	0.66
i4	Single-turn	6.67	2.00	0.30	0	0	79	0.00	0.00
i5	Single-turn	5.11	1.84	0.36	4	5	70	0.24	0.13
i6	Single-turn	6.24	1.81	0.29	0	15	64	0.16	0.21
i7	Double-turn	7.57	1.59	0.21	8	16	55	0.45	0.53
i8	Double-turn	3.19	1.37	0.43	20	10	49	0.75	0.33
i9	Double-turn	2.68	0.51	0.19	47	24	8	0.46	0.46
i10	Full-turn	1.91	1.53	0.80	9	19	51	0.48	0.39
i11	Full-turn	2.27	1.41	0.62	1	45	33	0.27	0.44
i12	Full-turn	2.96	1.48	0.50	8	25	46	0.46	0.31

Item difficulty ($\frac{\overline{M}}{E}$), quantified by the ratio of the mean performance in the sample ($\overline{M}$) to the expected value ($E$) given the number of doors and number of partially correct answers in the respective trial; the absolute frequency of 0, 1, and 2 points scored in the sample; the variance ($s^2$) and corrected item-total correlation quantified by Wilson’s $e$