Thinking Routines / 3-2-1 Bridge
3-2-1 Bridge
Three words, two questions and one analogy — collected before you teach a topic, then again at the end. The gap between the two columns is the lesson.
Opens on the whiteboard to model with the class · no sign-up · printing is optional
The sheet it prints — optional
What is the 3-2-1 Bridge thinking routine?
3-2-1 Bridge is a thinking routine run twice on the same topic. Before teaching, a class gives three words, two questions and one analogy. After teaching, they give three more of each without looking back. The bridge is their explanation of what changed.
How do you run 3-2-1 Bridge with a class?
Take the first response cold, before any teaching, and put it away. Teach the topic. Take the second response without letting anyone reread the first. Only then put them side by side and ask what moved, and what moved it.
Why must they not reread the first column?
Because a child who can see their earlier answer will edit towards it or away from it, and either way you stop measuring anything. Answering cold produces an honest second response, and the contrast is what makes the routine worth running.
Do not skip the analogy because it takes longest. It is the single most diagnostic thing on the sheet — a child who writes 'the water cycle is like a washing machine' has understood something a list of three words would never have shown me, and a child who writes 'it is like water' has told me just as much in the other direction. I now read the analogies first when I collect these in, and plan from those.
Which subjects does 3-2-1 Bridge suit?
Any topic children arrive with half-formed ideas about.
- Science — the body, space, forces, anything with folklore attached.
- History — a period they think they know from films.
- Geography — a country or a way of living unlike their own.
- RE — a belief or practice they have heard of but never examined.
What usually goes wrong with 3-2-1 Bridge?
The first half never gets collected, because it has to happen before you start teaching and that is easy to forget. Put it in the planning for lesson one, not lesson two, or there is nothing to bridge from.
Which year groups is 3-2-1 Bridge for?
3-2-1 Bridge suits Year 3 upwards, grade 2 in the US. Younger children manage words and questions but find analogies hard, so drop to 3-2 with Years 1 and 2. From Year 6 the analogy is usually the most revealing part of the whole page.
What do you do with it afterwards?
Read the analogies first. They are far more diagnostic than the word lists, and comparing the before and after analogy for one child tells you more about what they now understand than a test would. Keep the sheets — they are strong evidence of progress for anybody who asks.
How often should you use 3-2-1 Bridge?
Once per unit, in two halves. Any more and the second response starts echoing the routine rather than the learning. It is one of the few routines here that has to be planned in advance rather than reached for.
What if the two responses look almost the same?
That is a finding, not a failure. Either the topic did not shift anything, which is worth knowing before you move on, or the class is repeating the first response from memory. Ask them to explain a word they used both times — the explanation usually changed even when the word did not.
| Year group | US grade | What to change | How long |
|---|---|---|---|
| Years 3–4 | Grades 2–3 | Three words and two questions. Analogy optional. | 10 min each half |
| Years 5–6 | Grades 4–5 | All three. Insist the analogy is explained. | 15 min each half |
| Year 7 and up | Grade 6+ | Add: which of your first questions never got answered? | 20 min each half |
3-2-1 Bridge compared with Connect, Extend, Challenge
Both look back at learning. Connect, Extend, Challenge is a plenary you can run on any lesson. 3-2-1 Bridge needs planning, because half of it has to be captured before you teach anything — but it shows the change far more convincingly.
Free · no sign-up to run it · printing is optional
Where this routine comes from: the 3-2-1 Bridge thinking routine was developed by Project Zero, a research center at the Harvard Graduate School of Education. Sage Teachers is not affiliated with, endorsed by, or connected to Harvard University or Project Zero. The prompts and the wording on this page are our own.