On Thu, May 15, 2014 at 3:56 AM, Nuria Ruiz <nuria@wikimedia.org> wrote:

We decided to switch to a localStorage based solution. In your case I
think with UserTimings and sessionStorage you could get you the data
you need. Support for storage is broad:
http://caniuse.com/#feat=namevalue-storage, support for user timings
less so but you get chrome and IE and that is a big percentage of
user base: http://caniuse.com/#feat=user-timing

I don't see how UserTiming is related. That API is about obtaining sub-millisecond precision - that is useful when you are building a 3D rendering engine or similar extremely time-sensitive feature, but generally using regular millisecond numbers is OK.

> what if the user comes back after a month?

If you use session storage the events disappear when the user closes
the browser.

That means we are biasing the stats towards successful users, as they are guaranteed to make another page load in the same session, while unsuccessful ones might just leave for a while.

Trying to compensate for that by making guesstimates, as you suggest, is a path I would rather not take.