[time-nuts] Can ADEV of a frequency source be correctly determined using a continuous time-stamping frequency counter?

[Erik Kaashoek]

As far as I understood the ADEV at a Tau of 1 second is a statement 
about the amount of variation to be expected over a one second interval.
It would be nice if we would be able to measure a frequency in an 
infinite short interval but any frequency measurement takes time.
What if the frequency counter does a complete measurement of a frequency 
source every second and all the variation within that second is hidden 
because of the "integration" that happens over the second?
This is specially the case with continuous time-stamping counters.
They can provide a precise number by applying statistical methods on 
many measurements done during one second but they can not provide 
information exactly at the end of a second.
Is this kind of statistical measurement over a period of a second still 
valid for determining the ADEV at the Tau of one second of a frequency 
source?
Or should there be a correction factor depending on the method used in 
the frequency counter?
I tried to read some scientific studies on this subject but I am not 
smart enough to understand.
Hope one of you can provide some information.
Erik.