Reading an editorial

Every editorial has the same shape, so once you have read one you know how to read them all.

The anatomy of an editorial

An editorial opens with a hook: one sentence saying what is surprising or non-obvious. It is the same hook used on Instagram. The problem comes next, the concrete question being answered, followed by the idea, the key insight stated before any heavy algebra.

After that comes the interactive visualization, headed "Try it". Change the inputs, step through it, and try to break it. The full proof follows, with every step written out. Tags at the end are short labels for finding related editorials.

The visualization sits between the idea and the proof on purpose. You should see the claim before you read the argument for it.

Principle and error type

Near the top of every editorial are two labels. The principle is the general idea the editorial teaches, such as a technique that applies well beyond the one problem. The error type is the specific mistake it corrects, when there is one.

Both are free text for now, because the vocabulary is still settling as more editorials are published. The archive filters use them, so following a principle from one editorial to the next is a good way to find more on the same idea.

Mathematics

Formulas are typeset with KaTeX at build time, so they appear immediately and do not reflow after the page loads. Screen readers get the formulas as accessible MathML as well as the visual rendering.

Reading with the syllabus

An editorial or material can be linked to a syllabus topic. When it is, its page links back to that topic, and the topic's row in the syllabus links forward to it. Use the syllabus as the table of contents and the editorials as the deep dives.