Research a topic before writing

A lesson is only as good as the understanding behind it. Do this first, then hand the outline to the new-lesson skill. Never write lesson prose from memory alone for anything non-trivial.

Read TOPIC.md first — it is the single source of truth for the subject, mission, and scope. Research the subject as a step on the zero-to-expert ladder that TOPIC.md defines. Identify the lowest level of prior subject knowledge a reader could have (beginner tiers assume none), and flag every domain term, prerequisite, and assumed-but-untaught concept so new-lesson can set the right difficulty and dependencies. Push the brief to genuine expert depth, not just an intro.

1. Gather sources

• Use WebSearch / WebFetch for current, authoritative sources. Prefer primary sources, standards, docs, and well-regarded explainers over SEO blogs.
• For academic/scientific topics, use the paperhound skill (arXiv, OpenAlex, Semantic Scholar) to pull real papers and abstracts.
• Cross-check any non-obvious claim against ≥2 independent sources. Note where experts disagree.

2. Produce a research brief

Capture (keep it in the working notes / hand to new-lesson):

• Audience & prerequisites — who is this for, what must they already know.
• Learning objectives — 3–6 concrete "after this lesson you can…" outcomes.
• Key concepts — each with a crisp, correct definition (these feed the glossary / concept → definition exercises, see the exercise-components skill).
• Common misconceptions — what learners get wrong (great quiz material).
• Analogies & mental models — at least one strong analogy per hard concept (feeds the copywriting voice, see lesson-copy).
• Worked examples / concrete numbers — real data beats hand-waving.
• Animation opportunities — which idea is best shown moving, not told (feeds lesson-animations).
• Sources — list URLs/citations so claims are traceable.

3. Plan the lesson shape

• Split the topic into a topic + ordered lessons (one idea each, ~5–8 min).
• For each lesson, draft the 2–6 ## section outline and pick at least one exercise and at least one animation that earns its place.

4. Accuracy gate

Before writing: re-read the brief and confirm every definition and claim is something you can defend from a source. Flag anything uncertain to the user rather than inventing it. Then proceed to new-lesson.