Table 2.

Classification performance of support vector machine (SVM) classifiers for nonmedical use of methylphenidate.

SVM classifier	F1 score for nonmedical use	F1 score for negative	Precision	Recall	Accuracy
Final model	0.547	0.983	0.926	0.388	0.967
Without nonmedical use terms	0.145	0.975	0.933	0.079	0.952
Without medical use terms	0.506	0.982	0.925	0.348	0.965
Without personal noun	0.233	0.976	0.857	0.135	0.954
Without sentiment scores	0.420	0.979	0.833	0.281	0.960
Without a URL	0.526	0.982	0.923	0.368	0.966