MIT CSAIL Foundations

ML Beginner's Interactive Lab & Decision Boundary Workbench

MODEL: 2-Layer MLP
EPOCH: 0
LOSS: 0.693
TRAIN ACC: 50.0%
2D Feature Space & Decision Heatmap x₁ ∈ [-1, 1], x₂ ∈ [-1, 1]
Probe: hover on canvas 48 Points (24 Teal, 24 Magenta)
Model Architecture & Training
Hidden Units: 6
Learning Rate (η): 0.080
Training Loss History 0.693
Interactive Query Probe
Input (x₁, x₂): (0.00, 0.00) Raw Logit (z): +0.00 P(Class A): 50.0% Predicted: Tie / Ambiguous
1. Non-linear XOR Problem Minsky & Papert 1969

A single linear hyperplane cannot separate diagonals (XOR). A 2-layer MLP transforms the feature space into curved non-linear decision regions.

2. Linear Separators Perceptron & Logistic

Computes \( \hat{y} = \sigma(w_1 x_1 + w_2 x_2 + b) \). Perfect for clean linearly separable data, but fails on complex manifold topologies.

3. Non-Parametric Boundaries k-NN & Decision Trees

k-NN creates Voronoi-like local decision pockets without weights. Decision trees create orthogonal axis-aligned partition boxes.

4. Learning Rate & Dynamics Gradient Descent

Too small \(\eta\) leads to glacial convergence; too high \(\eta\) oscillates wildly across loss ravines. Observe how loss trajectories morph.

Enjoy this tool? Build your own with Super