apparent variation

10:55 Nov 15, 2014 

I think Václav's comment "Hlavně bych navrhoval obezřetnost u slova apparent, což může být zjevný, shledaný, či zdánlivý/domnělý ... mně v tomto kontextu nejvíc sedí apparent ve smyslu 'as found to be'" is completely accurate.

12:37 Nov 14, 2014 

This is the first case when "variation" is used in the text:

The object of drawing samples is generally to estimate some features of the population from which they are drawn, in order to make inferences about that population.
In reference testing and quantity control, this object can be narrowed down to estimating the average and variation of prepackage contents, or the proportion non-standard, in the batch, group or process.

Some other occurrences are:

The pattern of variation in these estimates is described by sampling distributions.

The precision of an estimate obtained by sampling is measured by its standard error - in its statistical usage, the standard error is treated in a similar manner to the standard deviation, but the term standard error is used in connection with sample estimates of parameters, the standard deviation measuring the variation in the original variable.

Further details of control procedure and methods for formulating target quantities to take account of the underlying process variation, appear in Annex E of this Manual.

If the standard error of the sample means, which may depend on a medium-term variation as well as variation between items...

12:32 Nov 14, 2014 

Roughly speaking Total variability = Process variability + Random variability.

I'd have thought that "kolísání" refers more to the latter?

"přirozené variability (náhodného kolísání). ... Celkovou variabilitu (rozptyl) sledované proměnné lze rozdělit na 2 složky"

"velikost kolísání všech platů (celková variabilita)"