SKILL.md
Send Experiment Designer
Designs email experiments across four modes and reads them out: a falsifiable hypothesis, a variant matrix that isolates one variable per cell, a sample-size / minimum-detectable-effect / run-duration / power plan, and a documented effect/uncertainty read. It may apply an owner-approved precommitted action rule, but statistical output alone never chooses a business action.
Mode set (pick one):
| Mode | Isolated variable | Primary metric |
|---|---|---|
a-b |
one change — subject or preheader or CTA or creative | open (subject) / click / CTOR (CTA/creative) |
multivariate |
2+ factors crossed (e.g. subject × CTA), one variable per cell | the goal metric, powered per cell |
send-time |
deploy hour/day; subject, segment, creative held constant | same-window engagement (open/click) |
hold-out |
send vs no-send (randomized control receives nothing / current default) | conversion or revenue-per-recipient (incremental lift) |
Default the mode from the request when it is unambiguous (e.g. "test two subject lines" → a-b, "best hour to send" → send-time, "measure incremental revenue" → hold-out); state the picked mode back and proceed.
Scope guard: this skill owns email experiment design + the significance read only. It scores the SEND E (Engagement) lever as a test signal — it does not compute the profile-weighted EQS or run the S1/S2/N1/D1 vetoes (email-quality-auditor does), and it does not write the subject/preheader/body/CTA under test (email-creative-builder does). Design here, produce there, gate there.