Thinking Like a Historian
Stop memorizing dates and start solving mysteries. Learn how to evaluate evidence, spot bias, and piece together the stories of the past like a professional detective.
Like Duolingo, but for Thinking Like a Historian. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
A short one: 9 levels across 2 sections, about 18 minutes end to end, roughly 4 days at five minutes a day. It moves through The Detective's Toolkit and Connecting the Dots. It starts from scratch.
Free forever · No credit card · iPhone & Android

Key ideas in Thinking Like a Historian
- Primary sources are created by people present at the event
- Secondary sources interpret and combine multiple primary clues
- A diary entry written the day of the disaster is firsthand evidence
- Primary sources are the raw materials of history
- Later summaries are not primary sources
- The timing of the creation determines the source type
- Identifying primary sources as firsthand evidence
- Distinguishing between raw evidence and historical synthesis
- Written records reflect self-image
- Trash reveals reality
- Primary sources as firsthand evidence
- Physical evidence lacks agenda
- Gaps point to lack of power
- Raw evidence vs synthesis
- Omission is a deliberate choice
- Absence as a clue to hierarchy
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives Thinking Like a Historian the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
What is the main role of a secondary source in historical research?
Get it right to open this lesson and 8 more in the app.
Where Thinking Like a Historian takes you
- 1
The Detective's Toolkit
- Finding the Clues
- Questioning the Witness
- 2
Connecting the Dots
- The Power of Context
- Why the Story Changes
2 sections · 4 units · 9 levels. Built to play, not to enroll.
Tomo is in ChatGPT
Tomo is also a ChatGPT plugin: the same playable courses, built and played inside your chat.
Add Tomo to ChatGPT- What to ask
- “Make me a Tomo course on black holes.” “Turn this chat into a Tomo course.”
- What you get
- Quick questions with instant feedback, hearts and stars, ready to play in about a minute.
- Where it goes
- No sign-up to start. Connect your Tomo account and your streak carries on in the app.
You pick the voice
Thinking Like a Historian is taught in the Professor style: clear, structured, thorough. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
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Start Thinking Like a Historian today.
Download Tomo, search Thinking Like a Historian, and play your first lesson in under a minute.