ARENA visual explainers

Understand the chapter before the notebook starts.

These pages are for the layer before implementation. They make the main idea, the key mechanism, the contrast case, and the carry-away mental model legible before you start tracing code line by line.

What they are. Student-facing chapter companions built around explanatory structure instead of notebook order.
What they are not. They are not replacements for ARENA. They are the bridge that helps the notebook feel coherent faster.
Main idea → mechanism → contrast → notebook bridge

The chapter pages are built to answer the same student questions in roughly the same order, so they feel like one family instead of unrelated summaries.

Concept-first, visual, and discussion-ready

If a page helps you predict what the notebook is about to show you, it is doing its job.

01 · what these pages do

Each explainer is trying to make one chapter teachable before it gets technical

The public surface is intentionally narrow. These pages foreground the chapter’s real mechanism and the mental model a student should carry into the notebook.

first question
What is this chapter really about?

The page should name the real conceptual center, not just the sequence of exercises.

mechanism
What is the simplest version that still clicks?

Students need one clean story before they need all the details and variants.

contrast
What misconception gets corrected?

The pages try to sharpen intuition by showing the wrong read next to the better one.

bridge
What should I expect in the notebook?

Plots, code, hooks, or metrics should feel like evidence for a story the student already understands.

02 · current chapters

The pages differ by chapter, but they keep the same editorial spine

Each one emphasizes a different mechanism family, while preserving the same study-companion feel.

TransformerLens, induction circuits, and how reverse engineering gets its evidence

A chapter companion organized around circuit tracing, skip-trigrams, induction heads, and the ladder from pattern to mechanism claim.

Main mechanism: how attention circuits copy and continue patterns
Key contrast: QK-style matching versus OV-style copying
Carry-away model: mechanistic interpretability is about building evidence for a causal story
Open explainer

Convolution, residual paths, and why ResNet-style training changes what becomes easy

A student-facing explainer centered on locality, receptive fields, residual learning, and how BatchNorm and skip connections stabilize deep vision models.

Main mechanism: local feature detectors stack into richer spatial hierarchies
Key contrast: plain deep nets versus residual networks
Carry-away model: depth becomes practical when optimization has an easier path
Open explainer

Truth directions, readable geometry, and why patching is the stronger test

A chapter companion for linear probes, built around the final-token truth setup, MM versus LR, transfer across datasets, and why intervention matters more than readout alone.

Main mechanism: find a truth-related direction in activations at the right readout site
Key contrast: readable feature versus causally used feature
Carry-away model: a probe becomes more meaningful when the answer moves too
Open explainer
03 · how to use them

Treat this like a cover page for a visual textbook, not a gallery

The intended flow is simple: orient first, then verify in the notebook while the underlying mechanism stays in view.

1. Open the chapter page and get the main idea straight.
2. Learn the simplest mechanism and the contrast that makes it click.
3. Carry that mental model into the notebook, then let the plots and code confirm it.
4. Come back after the exercises if you want the two-minute recap version.
ARENA is often hardest at the start, when the student does not yet know what deserves attention.

These pages try to lower that cold-start cost. They narrow the visual field so the first notebook pass feels like confirmation instead of confusion.