Wikimedia Bugzilla is closed!

(ported from https://github.com/rfaulkner/E3_analysis/issues/37)

The API should return for each record in a raw response a code specifying whether the value is defined or the reason for an undefined/missing value otherwise.

The most common example of an undefined value in a metric response is when the difference between the time of a request and the user registration time is smaller than the default value of t (currently set to 24 hours), in which case the API cannot compute the value of the metric for the user (technically, this is a right-censored observation).

Censored observations should always be flagged in the raw response and reported but excluded from the metric in any aggregate response.