STOR 323 · Lecture 3

ML pipeline: from data to decisions

A set of interactive lessons built around one lecture deck — the pipeline that turns a dataset into a deployed decision.

Lessons

#LessonCovers
1From data to decisionsThe core pipeline: D→A→f^_D, then x→f^_D→s→δ→a
2Beyond the straight lineLinear vs. softmax regression vs. kNN — parametric vs. nonparametric
3Evaluation: how good is "good"?MSE, ROC/AUC, confusion matrices, thresholds, and group fairness
4Build the policyInteractive review exercise — the whole arc, one decision at a time
5Shape and stackingPerceptron, linear separability, XOR, and the multi-layer perceptron
6How the stack learnsThe perceptron's simple nudge rule, credit assignment, backpropagation, and why activations went smooth
7The hierarchy, and where transformers fitAI ⊃ ML ⊃ neural network ⊃ transformer, attention, GPT, and where models still break
8How much data is "huge"?Grounding "trained on a huge pile of text" in real, sourced numbers
9The scale surpriseSame training objective, huge scale — why capability like coding and translation shows up unasked
10Historical contextThe people, dates, and accidents behind lessons 0005–0009, in order

Homework 1

#LessonCovers
11Homework 1: the mapHow each problem maps to lessons 0001–0010, plus the new notation at a glance
12Thresholds and policyConfusion matrix, TPR/FPR, capacity-constrained thresholds, grouped validation splits
13Log loss and one gradient descent stepSigmoid, log loss, the gradient, one GD update, and why L2 regularization is needed under separation
14Softmax and deploymentCategorical labels, softmax probabilities, log loss vs. classification error, a confidence threshold that routes to a human
15Regularization can prefer a shortcutL1 vs. L2 penalty arithmetic and geometry, spurious features and audits
16The V-shaped gateBonus — two ReLU units composing into |x|

Reference

PageCovers
Notation decoderEvery math symbol from the deck, explained with pictures and real-world analogies
GlossaryEvery term from the deck, one place, quick lookup