Table 3 Difference in average number \( \left(\boldsymbol{\Delta} \overline{n}\right) \) of correct answers on subsequent problems per student between D&D and MC format

n

3

5

5

5

5

\( \overline{n} \)(MC, 1st attempt)

0.36

0.94

1.94

2.09

1.08

\( \Delta {\overline{n}}_{\mathrm{D}\&\mathrm{D}\hbox{-} \mathrm{M}\mathrm{C},\ 1\ \mathrm{attempt}} \)

0.73^a

0.75^b

0.64

0.79

0.02

p (U test)

0.007

0.02

0.25

0.07

0.89

\( \overline{n} \)(MC, 2 attempts)

1.68

2.27

3.54

3.74

2.77

\( \Delta {\overline{n}}_{\mathrm{D}\&\mathrm{D}\hbox{-} \mathrm{M}\mathrm{C},\ 2\ \mathrm{attempts}} \)

1.12^a

−0.15

1.19^b

1.1^c

−0.54

p (U test)

<0.001

0.9

0.03

0.02

0.15