Multiple-Choice Randomization

Figures & data

Table 1. Summary of exam score means and standard deviations for each treatment combination.

	Number of Students	Exam score mean	Exam score standard deviation
(a) I & O random	108	52.45	11.88
(b) I partial & O random	114	53.75	13.06
(c) I random & O fixed	107	54.72	12.65
(d) I partial & O fixed	113	53.40	11.32

Table 2. Summary of exam score means and standard deviations for each factor level.

	Number of Students	Mean	Standard Deviation
I random	222	53.12	12.49
I partially random	220	53.70	12.00
O random	215	53.58	12.29
O ordered	227	53.24	12.21

Table 3. Analysis of variance table for our experiment.

Source	DF	Sum of Squares	Mean Square	F-Value	Pr > F
First mid-term covariate	1	18840.121	18840.121	176.536	< 0.001
Factor I (item)	1	44.651	44.651	0.418	0.518
Factor O (answer-option)	1	0.449	0.449	0.004	0.948
Error	440	46637.210	106.721