TABLE 1.

Results of the German field test data 2014 for the mode effect, based on the 1PL Model.

	All items							Invariant items
Domain	N			d		SDmode			d		SDmode
	PBA	CBA	I	Est	SE	Est	SE	I	Est	SE	Est	SE
Science	340	338	77	−0.23	0.08	0.17	0.05	56	−0.17	0.08	0.13	0.06
Mathematics	345	340	66	−0.14	0.07	0.31	0.05	36	−0.09	0.07	0.27	0.08
Reading	349	334	82	−0.13	0.10	0.43	0.05	47	−0.06	0.09	0.25	0.07

N = number of students; I = number of items; PBA = paper-based assessment; CBA = computer-based assessment; d = effect size for mode effect CBA vs. PBA (negative effect: disadvantages of CBA); Est = estimate; SE = standard error; SD_mode = standard deviation of the difference between item difficulties in CBA and PBA mode; Statistically significant (p < 0.05) d values are printed in bold.