TABLE 3.

Analysis of most frequent incorrect answer (MFIA) for six challenging questions. Misinterpretation Index (MI) on pre- and posttest are indicated.

Question	Skill	Answer	MFIA	MI pre	MI post
2	describe patterns in data	D	B	0.86	0.97
4	propose next experiment	A	B to D*	0.38	0.46
7	propose experimental control	A	B	0.57	0.68
8	generate conclusions	C	B	0.74	0.83
15	generate conclusions	C	E to D*	—	0.52
16	propose next experiment	A	D	0.40	0.42

^*Indicates that the MFIA was different between pre- and posttest.