Students (# = 32)

Group A + B

Mean hit rate (# of answered pairs/40 × 32)

0.6805 (871/1280)

(2834 words)

Estimated density $p_{A+B}$

0.1078

[# of each type in 871 answered pairs]

AA = 162, AB = 427, BB = 282

Group B

Mean hit rate (# of answered pairs/40 × 32)

0.5961 (763/1280)

(1744 words)

Estimated density $p_{BB}$

0.0867