Comparison in the quality of distractors in three and four options type of multiple choice questions

Figures & data

Table 1 Discrimination index for 3 and 4 options test, together with Kr-20 values

Discrimination index
	3 options test	4 options test
Mean	0.260	0.280
S.D	0.133	0.155
	Kr-20
Kr-20	0.820	0.830
Difficulty index
	3 options test	4 options test
Mean	0.85	0.83
S.D	0.13	0.15
Kr-20	0.82	0.83

Note: Bold data indicates acceptable reliability.

Abbreviations: S.D., standard deviation; Kr-20, Kuder-Richardson Formula 20.

Table 2 Discrimination index

Option 3 > Option 4	Discrimination index					t	df	Sig. (2-tailed)
	Mean	S.D	Std. error mean	95% confidence interval of the difference
				Lower	Upper
	0.02500	0.07841	0.01240	0.05008	0.00008	−2.816	39	0.038

Abbreviations: S.D, standard deviation; Std., standard; df, degrees of freedom.

Table 3 Difficulty index

Option 3 > Option 4	Difficulty index					t	df	Sig. (2-tailed)
	Mean	S.D.	Std. error mean	95% confidence interval of the difference
				Lower	Upper
	0.02488	0.04255	0.00673 3 options	0.01127	0.03849 4 options	3.698	39	0.001

Abbreviations: S.D., standard deviation; Std., standard; Sig., significance; df, degrees of freedom.

Table 4 Average mark in both sets of MCQs

Set	Average mark	P-value
Set 1	34.163	0.0001
Set 2	33.140

Abbreviation: MCQs, multiple choice questions.

Table 5 Details regarding functioning distractors index

Distracter Index
Number of functioning distractors	3 options		4 options			P-values
	Frequency	%		Frequency	%
0 distractors	10	25	0 distractors	2	5	0.0391
1 distractors	16	40	1 distractors	13	33	0.7100
2 distractors	14	35	2 distractors	10	25	0.5410
3 distractors	N.A	N.A	3 distractors	15	38	N.A
Total	40 questions		Total	40 questions

Abbreviation: N.A, not applicable.