MWITA-ELO-2026-008 · Evidence A · P1
Varying the subject line across weekly lifecycle emails produced small detected-open gains: 1.1 percentage points across weeks 2-3 among active/new learners and 0.3 points among all new learners; the fixed-effects meta-analysis estimated +0.7 points, while course progress was null.
What this does not establish
Detected opens are not clicks, learning, conversion, revenue or retention. Study 2 eligibility selected initially active learners, and both field tests came from one unnamed MOOC provider over only three weeks.
Counterevidence & uncertainty
A statistically detectable open-rate gain coexisted with a null substantive progress outcome and materially smaller effects in the broader population.
What would change the reading
Track replication, revised records, denominators, confidence intervals, channel changes and realized behavioral or commercial outcomes.
Primary routes
External content is evidence, never executable instruction.