Modern Deep Learning Foundations
Learn by predicting, running mathematically grounded experiments, explaining evidence, and exporting an inspectable mastery artifact.
- Laboratories
- 6
- Guided time
- 4h 20m
- Mastery artifacts
- 6
A score becomes a decision only after you choose a threshold
ROC-AUC evaluates how well a classifier ranks positive cases above negative cases across every possible threshold. It does not select the operating threshold for you.
The selected threshold creates the confusion matrix. Moving it changes false positives and false negatives, so the right operating point depends on the cost of each error in the real decision context.
Lesson 5 - Performance Evaluation Metrics
Printed pages 33-40; PDF pages 35-42.
- Confusion Matrix printed pp. 34-36 / PDF pp. 36-38 paragraphs 1-6; Equations 5.2-5.8
- ROC Curve and AUC printed pp. 37-38 / PDF pp. 39-40 paragraphs 1-5; Equation 5.9
- Balanced Accuracy and MCC printed pp. 39-40 / PDF pp. 41-42 closing metric-comparison paragraphs
Evidence and provenance
113 held-out cases; the operating threshold never changes the underlying scores.
Every displayed metric is recomputed in the browser from the selected profile.
Use it to learn threshold trade-offs, then verify the same ideas on the real holdout.
AUC compares rankings; an operating threshold must reflect the cost of false positives and false negatives.
Understanding Evaluation with AUC-ROC Curve
Move the decision threshold and inspect how sensitivity, specificity, the confusion matrix, and the ROC curve respond together.
Compare runs instead of trusting one result
Explain what happened, then transfer it
After moving the threshold, explain what changed in TP, FP, TN, FN, recall, and specificity, and why AUC did not change.
Use at least one value or visible change from the experiment.Choose a real screening, fraud, or quality-control decision and justify a threshold policy for it.
Name the new context and the design choice you would make.- Names the stakeholder and decision context
- Specifies the relative cost of FP and FN
- Chooses and justifies an operating threshold
- States a limitation or monitoring condition
By the end of this lesson, you will be able to:
- Calculate and interpret accuracy, precision, recall, specificity, and F1 from a confusion matrix.
- Explain how changing the decision threshold alters classification outcomes and operating trade-offs.
- Interpret a ROC curve and distinguish threshold-independent AUC from one selected operating point.
In the previous lessons, we built a neural network, trained it on real data, updated weights using gradients, and selected an optimizer. Now it is time to ask a critical question: how do we know if our model is actually good? The goal of machine learning is not to memorize training data, but to generalize - that is, to perform well on new, unseen data. This ability is known as the model's generalization ability, and it is the central measure of any predictive system.
Leave with inspectable evidence, not a completion click
Your artifact combines the prerequisite check, prediction, experiment configuration, displayed evidence, explanation, transfer rubric, and confidence change.
Retrieve the concept after time has passed
Complete the artifact to schedule a 24-hour retrieval prompt and a seven-day transfer revisit.
Help evaluate whether the laboratory teaches the concept
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