Robustness of Linguistic Features:Syntactic Errors are More Important than Lexical
Table 4: Ratio of coefficients, calculated as Importancesyntactic/Importancelexical. Ratio higher than one indicates that syntactic features are more important for a classifier than lexical ones.
['Dataset', '[BOLD] Classifiers  [BOLD] NN', '[BOLD] Classifiers  [BOLD] SVM', '[BOLD] Classifiers  [BOLD] RF', '[BOLD] NB']
The lowest ratio is observed with DemB, and the AphB results are very close, suggesting that syntactic features are approximately twice as important than lexical features in predicting pathological speech. In healthy written language, the difference is even higher and reaches 7.15 for the random forest classifier.