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 | |------|-------------------|----------------| | | one change — subject or preheader or CTA or creative | open (subject) / click / C…