14. Evaluation Metrics
AI For Trading C1 L1 A12 Evaluation Metrics V2
Understanding Confusion Matrix and Model Accuracy
The confusion matrix is a useful tool in evaluating the performance of classification models. It compares actual and predicted classifications to identify where predictions were accurate or incorrect.
Example: Spam Email Classification
- Total Emails: 100
- Actual Spam Emails: 40
- Actual Non-Spam Emails: 60
- Model Predictions:
- Correct Spam Predictions (True Positives): 35
- Correct Non-Spam Predictions (True Negatives): 55
- Incorrect Spam Predictions (False Positives): 5
- Incorrect Non-Spam Predictions (False Negatives): 10
Key Metrics to Assess Models:
- Accuracy: Proportion of total correct predictions. For stock predictions, a small edge above 50% can be beneficial.
- Precision: Correct positive predictions compared to total positive predictions.
- Recall: Correctly identified positives compared to actual positives.
Contextual Differences in Fields:
- Investing: Small accuracy improvements can have a big impact.
- Medical Diagnosis: Requires high accuracy due to severe consequences.
- Spam Detection: Needs high precision and recall to avoid misclassifications.
- Sentiment Analysis: A 51% accuracy suggests difficulty in grasping nuances.
- Manufacturing Quality Control: Low accuracy leads to defects, necessitating high accuracy.
SOLUTION:
A confusion matrix is a table used to evaluate the performance of a classification model. It shows the number of true positives, true negatives, false positives, and false negatives, helping to measure the model's accuracy, precision, recall, and other performance metrics.SOLUTION:
Accuracy measures the overall correctness of a model by calculating the proportion of true positives and true negatives out of all predictions. Precision measures the accuracy of the positive predictions by calculating the proportion of true positives out of all positive predictions. Recall measures the ability of the model to identify all relevant instances by calculating the proportion of true positives out of all actual positives.