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

Table 5

The best feature combination after choosing the best trigger feature (1&2&3&4′&5) and best edge feature (1&2′&4&5&6&7′&8).

Task 1	Recall	Precision	𝐹-score
Strict evaluation mode	46.23	62.84	53.27
Approximate span and recursive mode	49.69	67.48	57.24
Event decomposition in the approximate span mode	51.19	73.21	60.25
Task 2	Recall	Precision	𝐹-score
Strict evaluation mode	44.90	61.11	51.77
Approximate span and recursive mode	48.41	65.81	55.79
Event decomposition in the approximate span mode	50.52	73.15	59.76

Recall = TP/(TP+FN), Precision = TP/(TP+FP), and 𝐹-score = 2((Recall×Precision)/(Recall+Precision)).