I want to look at 30 days of retention data by Operating System (iOS vs. Android) for users that have initiated at least one app session. I’m using a recurring retention report and the date range in question is 12/19/19 - 1/17/19. I’ve ran the report on three consecutive days and found that while the cohort sizes do not change, the number of users in certain time buckets for both cohorts grow. I attribute this to cohortized users showing up and being counted for the first time on the subsequent days. My questions are as follows:
- Should I infer that the time buckets are subject to grow until the last time bucket is reached e.g. 30 days past 1/17 when using a Day time unit?
- I would expect once this milestone is reached on 2/17 the time buckets become fixed - is this correct?
- Does this logic change at all if I use the Week or Month time units?
- Is there another way I should look at the data to avoid this issue? My concern is that I have to wait 30 days after my specified date range to get immutable retention data
Thanks for reading!
Best answer by stephanie
Going of what you have shared, when you have a breakdown in your retention report, your segment sizes won't change because they were all added up already - but your conclusion is right. For example, if someone did their first event on January 15th to get counted in the iOS bucket for this date range, but then they didn't act again until January 28th. This would still increase the 12 day bucket count by one, because everyone gets a timer from when they start. That means that February 17 would be the point at which these numbers wouldn't be able to increase anymore because even the last users will have already elapsed the 30 days, and either have counted or not.
The logic would change if you used the week or time units - if you switched to a month, February 17th of 2021 would be the last day (for the January 17th users to trigger the 12 month bucket).
Being that you are on the day view, you would have to wait until 30 days after the selected range to get an immutable view.
I hope this helps!