[Retracted] Automatic English Pronunciation Evaluation Algorithm Based on Sequence Matching and Feature Fusion

Table 2

Correlation coefficients between all features and expert ratings.

Characteristics of the	Correlation coefficientwith expert rating
Cosine similarity based on word frequency	0.753
Jaccard similarity	0.739
Dice coefficient	0.767
Manhattan similarity	0.762
Keyword coverage based on edit distance	0.646
The entire syntax tree is scored	−0.304
Syntactic tree score by sentence normalization	−0.381
Syntactic tree score normalized by word	0.051
Normalized syntax tree depth	0.386
The depth of the syntax tree	0.305
Sentence confidence score	0.631
The number of words per unit time	0.52