@madhuvishy do you mind leaving an update here based on the app comparisons we were trying to do and what is blocking that? thank you!

@leila and I were looking at the possibility of comparing mobile apps' UUID based uniques and the last access cookie based uniques only for apps - to see if they were close. After getting some initial numbers we found out since apps are not a browser client - the way they deal with cookies is different - and we may not be able to compare them this way. I'm gonna talk to someone on mobile apps to see how they handle cookies to better understand this. I am also currently working on getting separate numbers for the Android and iOS apps to see if the behaviors are different.

@madhuvishy, Thanks for this.

How hard it is in terms of engineering resources and otherwise to count uniques for a short period of time, say 24 hours, and compare the real count of uniques with the estimates that we get from LastAccess? We may be able to even consider a shorter period of time. My concern is us spending weeks to figure out a proper comparison in a case where we can compare LA counts with real numbers relatively cheaply (if that is indeed the case).

@leila Thanks for exploring this possibility

Work done on this is documented here: https://wikitech.wikimedia.org/wiki/Analytics/Unique_clients/Last_access_solution/Validation