A 3-2-1 reflection asks for three things you learned, two things that caught your interest and one question you still have. It takes about four minutes, and teachers have passed it around for so long that nobody can say who wrote it first. You will find it on printable exit tickets and in teacher guides, usually as the last thing a class does before the bell.

This page turns the three lines, two lines and one line into a small cairn of stones, the kind hikers stack to mark a trail. What you learned is the base, the two sparks rest on it, and your question sits on top, where it points the way to what you study next.

How the cairn works

Each stone is a line you write, and it stays a pale outline until you do. If a line won't come, tap a starter such as I learned that or What would happen if and finish it yourself. A starter on its own doesn't set a stone.

Give the cairn a topic, the lesson or unit it came from, and leave it on the trail. The trail keeps up to thirty-six cairns, about one per week for a school year, and each shows its date, its topic and a colored top stone: blue while its question is open, green once you've answered it.

Below the trail, your questions gather by topic. This is the part a paper exit ticket can't do. After a few weeks the page tells you which topic keeps raising questions and how many of them are still open. Tap answered when you find out. If you later rewrite a question, its answered mark clears, because the new words haven't been answered yet.

There is also a personal form for the end of a week or a project: three wins, two lessons and one focus. Those cairns stand on the trail too, with a gold top stone, but a focus isn't a question, so they stay out of the question pile.

Why you write the three from memory

The base does the most work, but only if you write it without looking. Pulling ideas back out of memory is a small test, and tests do more than measure. In Roediger and Karpicke's experiments, students who read prose passages and then wrote down everything they could recall remembered more two days and a week later than students who restudied the passages instead. The restudiers felt more confident about how much they would remember, and on those later tests they remembered less.

A large review of study techniques points the same way. Its authors rated practice testing as one of the two most useful techniques they examined and rated summarizing as low utility. A 3-2-1 copied off the board is summarizing. The same three lines written from memory is much closer to a practice test.

Why the question sits on top

Writing a question makes you find the exact edge of what you understand. A review of studies that taught students to generate their own questions about what they read found gains in comprehension, measured on tests of new material rather than the passages the students had practiced on.

Be honest about the limits, though. These studies tested free recall and question writing as separate practices. None of them tested a 3-2-1 sheet, so treat the research as support for the parts, not a verdict on the format.

Reading your trail

A topic with three open questions is the first thing to review before a quiz. Take those questions to class or office hours, and mark each one answered as it falls. When a whole topic stays stubbornly open, a from-memory review on the Blurting Pad will show you exactly which pieces are missing. Before a new unit, the KWL Chart records what you already know; the 3-2-1 picks up after each lesson.

For teachers

Print blank tickets from the sheet, two to a page, each with lines for a name, a date and a topic. Collect them at the door and read them as a stack. The Teacher Toolkit's write-up of the strategy calls reviewing the responses the most important step. Look for the points that repeat and for questions that gather around one part of the lesson; that part probably went too fast. Open the next class with the most common question.

The prompts can change to fit the lesson. Some classes use three takeaways, two questions and one thing they enjoyed; a compare-and-contrast version asks for three similarities, two differences and one question. Don't confuse any of these with the 3-2-1 Bridge from Project Zero, which asks for three words or thoughts, two questions and one metaphor or simile before a lesson and again after it, then has students explain how their thinking shifted.

When to use it

Stack a cairn in the last five minutes of a class, at the end of a week of lessons or when a project wraps up. For a group project, try the personal form first, then take the lessons to a Start, Stop, Continue with your team. Keep each stone to one plain sentence, and let the question be one you actually want answered.