표 5 분할된 하위집단별 문항 난이도 추정값(자료 C)

문항	Node 2	Node 3
The Exhibit - Q01	0.83	0.39
Book Covers - Q01	0.81	0.49
Book Covers - Q02	-0.95	-0.86
Book Covers - Q03	0.27	0.03
Library Accessibility - Q01	-1.31	-1.05
Library Accessibility - Q02	-0.02	0.88
Paper Products - Q01	0.37	0.11