1) Toy Numbers First
Before trusting a formula, feed it toy numbers that make the answer obvious (all 10s, or a single 1 among 0s). If the spreadsheet surprises you there, it’ll betray you later.
2) Sum or Average? Pick the Story
Sum tells you the pile. Average tells you the pace. If you want effort, sum. If you want consistency, average. The wrong summary metric answers a question you didn’t ask.
3) Format on Purpose
Units and formats aren’t decoration. Minutes vs hours, percent vs proportion… these choices steer interpretation. Decide once, label plainly, and stop explaining the same confusion twice.
4) Random Selection Is a Megaphone
When your sample is randomly selected, your voice reaches beyond the room you were in. No random selection? Speak softly about who you represent.
5) Random Assignment Is a Lever
Random assignment lets you push on “why.” Without it, effects are possibilities, not proofs. Use the lever when you can; use precise language when you can’t.
6) Convenience Is a Confession
If you sampled whoever was easiest, say so up front. Honesty keeps the result useful… even if its reach is small.
7) Stratify to Hear Quiet Voices
When small groups matter, don’t hope they show up. Guarantee it. Stratify so your conclusions don’t skip the story at the margins.
8) The Seven-Line Data Pitch
Who is in the data, how it was collected, when, how much, what it’s for, how to access it, and who owns it. Seven lines. Say them out loud before you share a chart.