Evidence Sentence

One written line, set down before you look at the evidence, that names your claim, the strongest competing explanation, the check you will run, and what you will do for each possible result.

Your Tuesday newsletter open rate jumped from 32 percent to 47 percent the week you switched to shorter subject lines. Someone posts the chart in the team channel with a fire emoji. By Thursday the plan is to rewrite every subject line in the queue. Nobody has said out loud what would count as this being wrong, and nobody has mentioned that the same week, a big podcast name-checked the newsletter and sent a wave of fresh subscribers.

An Evidence Sentence is one written line that fixes five things before you look: your claim, the best rival explanation, the probe, the results it could return, and the route you take for each. The cue is any moment a number has already picked a winner in your head. Here you would write: shorter subject lines lifted opens, not podcast traffic; the next four sends get split 50/50 by subject length, measured only on readers who subscribed before the podcast; a gap of 5 points or more and I rewrite the queue, under 2 points and I credit the podcast. Written first, the line turns Thursday's meeting into a date on the calendar instead of an argument. Skip it when the decision is cheap and easy to undo.