Table 3.

Basic statistics of the ontology-annotated text corpus.

Category	Value
Number of PMC articles annotated	51
# of sentences in all “Abstract” and “Methods” sections	3,866
# of sentences annotated with any concept	939 (24.29%)
# of tokens in all “Abstract” and “Methods” sections	118,709
# of tokens annotated with any concept	5,803 (4.89%)
# of tokens per concept instance	3.44
# of annotated concept instances	1,688
# of distinct concepts annotated	94
# of distinct concepts annotated only once in the corpus	19 (20.21%)