A Novel Feature Selection Strategy for Enhanced Biomedical Event Extraction Using the Turku System

Table 8

Analysis of average contribution of lexical features.

	Feature	Feature class	𝐹-score	Feature size	Average contribution
1	Nonstem	Main feature	6.43	154	0.04175
2	POS	Main feature	1.52	47	0.03234
3	dt	Content feature	20.13	1172	0.01718
4	tt	Content feature	27.63	7395	0.00374
5	Stem	Main feature	35.45	11016	0.00322