Table 4 Accuracy (%) of each classifier using the linguistic features in age-controlled experiments
Age between 60 and 75 | Age between 76 and 90 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
( p = 15, c = 25) | ( p = 13, c = 26) | ||||||||||
ID | Features | SVM | Bayes | CTree | NN | p value | SVM | Bayes | CTree | NN | p value |
1.1 | Question ratio | 70.0 | 67.5 | 70.0 | 60.0 | 0.011 | 66.7 | 35.0 | 38.5 | 43.6 | 0.037 |
1.2 | Filler ratio | 52.5 | 65.0 | 57.5 | 47.5 | 0.058 | 48.7 | 38.5 | 46.2 | 53.9 | 0.631 |
1.3 | Incomplete sentence ratio | 60.0 | 57.5 | 52.5 | 60.0 | 0.206 | 61.6 | 66.7 | 59.0 | 64.1 | 0.037 |
2.1 | Verb freq. | 37.5 | 62.5 | 47.5 | 50.0 | 0.114 | 69.2 | 61.5 | 53.9 | 59.0 | 0.016 |
2.2 | Noun freq. | 67.5 | 65.0 | 60.0 | 60.0 | 0.027 | 59.0 | 71.8 | 53.9 | 59.0 | 0.006 |
2.3 | Pronoun freq. | 72.5 | 72.5 | 65.0 | 47.5 | 0.004 | 69.2 | 66.7 | 56.4 | 59.0 | 0.016 |
2.4 | Adverb freq. | 52.5 | 62.5 | 52.5 | 52.5 | 0.114 | 59.0 | 41.0 | 38.5 | 43.6 | 0.262 |
2.5 | Adjective freq. | 57.5 | 47.5 | 45.0 | 42.5 | 0.343 | 51.3 | 43.6 | 51.3 | 51.3 | 0.873 |
2.6 | Particle freq. | 52.5 | 60.0 | 52.5 | 55.0 | 0.206 | 48.7 | 61.5 | 77.0 | 66.7 | 0.001 |
2.7 | Conjunction freq. | 62.5 | 62.5 | 65.0 | 52.5 | 0.058 | 53.9 | 56.4 | 56.4 | 46.2 | 0.423 |
2.8 | Pronoun-to-noun ratio | 70.0 | 70.0 | 67.5 | 62.5 | 0.011 | 71.8 | 66.7 | 61.5 | 46.2 | 0.006 |
3 | Unintelligible word ratio | 60.0 | 62.5 | 55.0 | 55.0 | 0.114 | 82.1 | 84.6 | 84.6 | 82.1 | <0.001 |
4.1 | Standardized word entropy | 55.0 | 65.0 | 45.0 | 57.5 | 0.058 | 74.4 | 64.1 | 59.0 | 56.4 | 0.002 |
4.2 | Suffix ratio | 45.0 | 52.5 | 55.0 | 60.0 | 0.206 | 69.2 | 74.4 | 64.1 | 53.9 | 0.002 |
4.3 | Number ratio | 70.0 | 67.5 | 70.0 | 65.0 | 0.011 | 48.7 | 61.5 | 51.3 | 48.7 | 0.150 |
4.4 | Brunet’s index | 62.5 | 57.5 | 67.5 | 65.0 | 0.027 | 48.7 | 59.0 | 61.5 | 56.4 | 0.150 |
4.5 | Honore’s statistic | 40.0 | 45.0 | 65.0 | 47.5 | 0.058 | 43.6 | 61.5 | 61.5 | 71.8 | 0.006 |
4.6 | Type-token ratio | 47.5 | 45.0 | 42.5 | 45.0 | 1.000 | 79.5 | 79.5 | 64.1 | 76.9 | <0.001 |