When using the HTML5 geolocation API I get, apart from latitude and longitude, also the "accuracy of the location in meters". What exactly does that mean (meters is not a unit of accuracy)?
I assume it shall be read as "with probability p the request was made within a meters of the returned location" - if so, what is p? Is it one standard deviation (p = 0.682?) Two standard deviations (p = 0.956?)
http://dev.w3.org/geo/api/spec-source.html isn't really explicit either.
Quoting from the spec:
The accuracy and altitudeAccuracy values returned by an implementation should correspond to a 95% confidence level.
So, 95% confidence level it is. Then again, implementations can vary significantly in what they report...