The sample was allocated across strata using disproportional allocation methodology [ 10], which increased the sample size for small strata and decreased the sample size for large strata.
Greater sampling intensity was allocated to strata with large predicted growing stock, and smaller sampling intensity to strata with small predicted growing stock.
The additional sample units can be effectively allocated to strata to reduce the standard errors of the regional estimates, even though these strata were not initially constructed for the objective of regional estimation.
In stratified random sampling, the sample size must be allocated to strata in order to optimize both objectives.
Moreover, it may outperform classical single phase designs if sample plots are appropriately allocated to strata with respect to predefined target variables, here: volume per ha of bigger trees of the main tree species.
Controls interviewed in each calendar year were randomly allocated to strata of interview lag time, proportionally to the distribution of the cases in the same calendar year, to obtain a similar distribution of lag time as in the cases.
Study clinics were randomly allocated, by stratum, to intervention or control using a computer-generated list of random numbers.
Similarly, he allocated the last three strata after all communities in those strata provided signed consent.
These were allocated into 38 strata.
The stratified design is a generalisation of the matched-pair design in which hospitals are grouped into homogeneous groups or strata according to the pre-defined characteristics, and then they are randomly allocated, within each stratum, to the intervention or the control group.
