Table 2.

Testing assumptions for quantitative items.

	Pilot study			Replication
Item	C1 z	C2 z	d	C1 z	C2 z	d	C3 z	C4 z	d
(3) Attrition	0.449	1.696∗∗	1.587	0.767	0.683	1.289	0.683	0.757	1.633
(4) Attrition between	0.77	0.873	2.31	0.667	0.536	2.799	0.49	0.595	2.244
(5) Exclusions after	1.335	0.57	0.692	0.451	0.513	2.974	0.38	0.506	2.974
(6) Follow-up	1.661∗∗	1.919∗∗	1.768	1.639∗∗	1.478∗	2.276	1.532∗	1.478∗	1.742

Items appear in abbreviated form; the whole and final version (after including improvements derived from the pilot study) can be consulted in the Appendix. C1–C4 = coder 1–4, respectively. z = Kolmogorov–Smirnov z to study normality assumption (accepted when p > 0.05). d = Durbin–Watson d to study independence of errors assumption (accepted when 1.5 < d < 2.5). Results that imply an assumption violation are in boldface.

^∗p < 0.05; ^∗∗p < 0.01.