SAS Output

Item Characteristic Curve and Item Information Function: Item50

Plot of iif * skill_level

Distracter analysis table: Item50

The FREQ Procedure

Frequency Col Pct

Table of A50 by Skill_level
A50(A50)	Skill_level							Total
A50(A50)	-2	-1	0	1	2	3	4	Total
A	4 36.36	23 17.56	43 8.05	10 1.10	8 0.93	0 0.00	0 0.00	88
B	0 0.00	48 36.64	355 66.48	822 90.23	822 95.25	452 98.91	239 99.58	2738
C	3 27.27	39 29.77	91 17.04	55 6.04	17 1.97	2 0.44	0 0.00	207
D	4 36.36	21 16.03	45 8.43	24 2.63	16 1.85	3 0.66	1 0.42	114
Total	11	131	534	911	863	457	240	3147
Frequency Missing = 37

Distractor analysis plot: Item50

Plot of prob * Skill_level = A50

Distractor analysis plot: Item50

KEY50
B