SAS Output

Item Characteristic Curve and Item Information Function: Item18

Plot of iif * skill_level

Distracter analysis table: Item18

The FREQ Procedure

Frequency Col Pct

Table of A18 by Skill_level
A18(A18)	Skill_level							Total
A18(A18)	-2	-1	0	1	2	3	4	Total
A	1 10.00	19 14.84	55 10.42	53 5.82	22 2.54	5 1.09	0 0.00	155
B	4 40.00	53 41.41	315 59.66	726 79.78	801 92.60	444 97.16	240 100.00	2583
C	3 30.00	27 21.09	94 17.80	80 8.79	21 2.43	7 1.53	0 0.00	232
D	2 20.00	29 22.66	64 12.12	51 5.60	21 2.43	1 0.22	0 0.00	168
Total	10	128	528	910	865	457	240	3138
Frequency Missing = 37

Distractor analysis plot: Item18

Plot of prob * Skill_level = A18

Distractor analysis plot: Item18

KEY18
B