Office hours are wasted the way most students use them — walking in with "I don't get it" and walking out with a re-explained slide they'll forget by Friday. The re-explanation felt productive; it trained nothing, because the help came before the attempt. The TA explained the concept; the student still can't produce it, and the exam doesn't allow a TA standing next to the problem.

The fix is to treat office hours as a stem factory, not a second lecture. Write two closed-book attempts before you go — real attempts, with the stuck point marked. Then ask the question the attempt made possible: "I tried X, I got stuck at Y, is the missing move Z?" The TA can answer that — a specific confusion has a specific fix. And whatever they reveal — the move, the shortcut, the exam framing — becomes a new stem you take home, not a relief you leave behind.

Why the re-lecture fails

Asking for a full re-lecture is asking the TA to do the retrieval for you. They explain, you nod, and the explanation stays theirs — you heard it, you didn't produce it. The re-lecture feels like help because the material is clear while they talk; it's not help because the clarity doesn't transfer to the exam where they're not talking.

The attempt-first question is different — a hint after an attempt is feedback, targeted at the exact move that failed. "I tried X, stuck at Y" tells the TA where the gap is; "I don't get it" tells them to start over, which means re-covering what you know to reach what you don't. A hint after an attempt is feedback; a hint before an attempt is a lecture you won't retrieve — and the exam tests retrieval, not having-been-lectured.

The office-hours workflow

Two closed-book attempts before you go. Not "I looked at it" — attempts: wrote the setup, got as far as you could, marked where it broke. The attempt is what makes the question specific: "I got stuck at Y" is a question; "I don't get it" is a fog. Two attempts is enough — one might be a fluke, two shows the pattern.

The first 30 seconds: the attempt summary. "I tried X, I got stuck at Y, is the missing move Z?" — the attempt, the stuck point, your guess at the fix. The TA can correct a move; they can't repair a fog. This opener respects their time and gets a real answer — the vague opener gets a re-lecture you'll forget.

Capture the hint as a stem, not a relief. Whatever the TA reveals — the missing move, the shortcut, the "that's the key step" — write it down as a question: "when [stuck point], the move is [their fix]." The hint is exam material the TA just revealed; capture it as a stem to practice, not a feeling of "oh, that's how" that evaporates.

End with the exam-verb question. "If you were writing the exam, what verb would you use on this?" — the TA knows the exam's framing better than you do. "Compare," "justify," "sketch," "derive" — the verb they say is the stem's instruction. Write it down; it becomes the format your practice mimics.

The new stem goes in the rotation the same day. Not tomorrow, not "when I review" — the same day, because the hint is freshest and the stem is most likely to be lost. A captured stem that waits is a captured stem that's gone; the same-day entry is the one that survives.

A 40-minute session on the clock

The weak opener is the fog — "I don't get it, go over it" — which gets a re-lecture covering what you know to reach what you don't. The strong opener shows the attempt (here's my page), names the stuck point (treated the constraint as solved), guesses the fix (keep g in the system), and asks the exam-verb question. The TA can correct a specific move in two minutes; the fog gets a sympathetic re-explanation that doesn't survive to the exam.

Why office hours are a stem factory

The TA's value isn't the explanation — it's the reveal. Every office hour produces exam material: the missing move, the common mistake, the exam's framing, the "I'd ask it this way." That's content you can't get from the slides, because the TA has seen the exam and knows what it tests. The students who leave with re-explained slides got the commodity; the students who leave with new stems got the insider material.

The capture is the discipline: the hint becomes a stem the same day, the exam verb becomes the stem's instruction, the stuck point becomes the stem's setup. Office hours done right is a manufacturing process — you bring raw attempts, the TA reveals the fixes, and you leave with production-ready exam questions. Done wrong, it's a second lecture you didn't retrieve either time.