Table I.

Erroneous ST Assignments for Top-Level STs

ST	Extent	# of concepts	SPC	LCA	SI	MC	# of errors	% of errors (95% CI)
Conceptual Entity	676	50	22	0	7	8	37	74 (61.8 – 86.2)
Chemical	27	27	12	0	2	5	19	70.4 (53.2 – 87.6)
Group	53	53	11	0	0	24	35	66 (53.2 – 78.8)
Anatomical Structure	127	127	13	0	49	7	69	54.3 (45.6 – 63.0)
Biologic Function	1398	50	1	0	17	9	27	54 (40.2 – 67.8)
Event	151	151	72	1	0	2	75	49.7 (41.7 – 57.7)
Activity	366	50	6	0	1	16	23	46 (32.2 – 59.8)
Entity	24	24	5	3	2	0	10	41.7 (22.0 – 61.4)
Phenomenon or Process	1596	50	3	0	16	1	20	40 (26.4 – 53.6)
Physical Object	47	47	4	0	1	8	13	27.7 (14.3 – 39.9)
Total	4465	629	149	4	95	80	328	52.1 (48.1 -55.9)
% of all errors	–	–	45.4%	1.2%	29%	24.4%	–	–

ST: Semantic type

SPC: more specific ST classification needed

LCA: Lowest common ancestor

SI: semantic inversion

MC: Miscategorization

CI: Confidence interval