Translations:Growth/Personalized first day/Newcomer homepage/Measurement and experiment plan/110/en

The duration of the A/B test is at least six months because it is impossible to detect changes to new editor retention on mid-size wikis in less time than that (unless we drastically impact retention, but we see that as somewhat unlikely). While we wait for our results we want to be able to take action if we suspect that something is amiss. Below, we sketch out a set of scenarios based on the data described in the instrumentation strategy above. For each scenario, we propose a plan of action to take to remedy the situation.