It was nice to know some things would be constant across space and time.
However, the cross-section of the beam has to be constant across the spans.
But how then can any species be constant in character across its entire range?
Though context effects can never be avoided, it is often desirable to hold them constant across all respondents.
Excess male mortality appears constant across the four very different countries included in the table.
Since is a constant across countries you should obtain the same estimate of it in this second case.
The effect is not constant across the sky due to differences in the matter/energy density at the time of last scattering.
Uniformity of law - the laws of nature are constant across time and space.
In the general case, there is no reason to expect this effect to be constant across individuals.
They are also constant through all human cultures and across historical time periods.