Recognition and Evaluation of Clinical Section Headings in Clinical Documents Using Token-Based Formulation with Conditional Random Fields

Table 4

Occurrence information.

Description	Feature value
The token was not matched.	000
The token only appeared in the first token among all section headings.	001
The token only appeared in the middle token among all section headings.	010
The token only appeared in the last token among all section headings.	100
The token appeared in both the first and middle tokens among all section headings.	011
The token appeared in both the middle and last tokens among all section headings.	110
The token appeared in both the first and last tokens among all section headings.	101
The token appeared in all places among all section headings.	111