Loop

A loop sends a step through again when its check fails, with the problem pointed out. It always has a limit on rounds, and at the limit it stops and flags the problem for a person.

Draft

The step writes a first try.

In a Real Template

The first step of the hand-off template has a check that sends the step back when it fails. The template says what happens on a fail, and a check that matters more stops the work instead.

A check that can send a step back

Each piece is hand over, keep or decide first

What happens when it fails

Run the step once more, and add what was wrong to the end of the prompt. If it still does not pass, fix it by hand and make a note of it.

A check that stops the work

Stop here. Fix the problem before you go on to the next step.

What to notice: The retry runs once more with the problem added to the prompt, then hands over to a person. A fault that must never get through does not loop at all: it stops.

From the template Hand off a task to someone else.

Easy to Mix Up

Best of severalA loop fixes one draft. Best of several makes more than one and keeps the best.
A repeat for every partSplit and merge runs a step on each part of a long file. A loop runs one step again after a failed check.
Trying again until it worksA loop has a limit, and each try is told what failed. Without a limit it can drift far from the source.

Go Deeper

Lesson 6: Loops with a limitPut a loop’s five moves in order.Loops and limitsSet the limit and decide what the loop does next.Loops, the parts guideDraft, check, revise, shown on a diagram.