Table 3. Results of Baseline and High-performing Models.
Baseline | 1 | 2 | 3 | |
Model Type | LASSO | Random Forest | Random Forest | Random Forest |
Metrics | ||||
Unlabeled data | Ignored unlabeled data | Assumed negative, ignored actual negative cases | Assumed negative, ignored actual negative cases | Assumed negative, ignored actual negative cases |
Imbalanced data | N/A | Downsample, class weight | Downsample, subsample balanced weight | Repeated random subsampling |
Validation method | 80% / 20% split validation | Nested cross validation | Nested cross validation | Nested cross validation |
Optimized metric in hyperparameter selection | None | F(beta=10) using 100 random iterations | F(beta=10) × 100 + PU score using 100 random iterations | F(beta=10) × 100 + PU score using 60 random iterations |
Scores | ||||
Fbeta=10 score (all data) | 0.32 | 0.71 | 0.71 | 0.72 |
PU score (all data) | 0.93 | 9.22 | 12.45 | 10.69 |
Recall (labeled data) | 0.92 | 0.81 | 0.77 | 0.80 |
Brier score loss (labeled data) | 0.10 | 0.14 | 0.16 | 0.15 |
Brier score loss (unlabeled data assumed negative) | 0.60 | 0.06 | 0.03 | 0.04 |
F1 score (labeled data) | 0.90 | 0.86 | 0.84 | 0.86 |
Precision (labeled data) | 0.88 | 0.91 | 0.93 | 0.91 |
Probability of unlabeled cases to be labeled as positive | 0.93 | 0.07 | 0.04 | 0.06 |
LASSO: least absolute shrinkage and selection operator; PU: positive-unlabeled