Sentence examples for survey strata from inspiring English sources

For these datasets, the variable to identify survey strata is called "stype", the variable for sampling weights is called "pw", and the "fpc" variable contains the population size for the stratum.

In total, nine different survey strata were defined (Figure 5).

Across survey strata, the availability of closed-understory terra firma forest (as measured on transects) was the sole and highly significant habitat predictor of elephant density (Elephant density = 0.00004closed understory forest−0.1159; R2 = 0.93; p = 0.0004).

Estimates were obtained with adequate, pre-defined levels of precision (25% CV for elephants and apes), with some notable exceptions: small sample sizes (LTCR elephants), lower-than expected encounter rates (Mokabi) and highly clumped distributions within some survey strata (e.g. elephants in Bailly and Loundougou, Figure 4).

In calculating the total sampling effort required in each stratum for a target CV of 25% [36] we used encounter rates of elephant dung and great ape nests in each of the survey strata from prior baseline data collected independently in each of the management units [19], [48], [49].

Multiple regression models, using survey strata and weighting, were conducted to examine the effect of each comorbidity on IQS and on the relationship between aASM and IQS.

Survey stratum limits followed the official limits in government or land-use decrees, with three exceptions.

For the first analysis stratified estimates for encounter rates, density and abundance were obtained for each survey stratum and the data were pooled to estimate detectability (models that stratified detectability by survey stratum were also considered).

The variance of encounter rate for each survey stratum and also for each habitat type within each stratum used in the first and second analysis respectively, was estimated empirically taking each transect line as a sampling unit.

We also included both survey stratum and X/Y coordinates as covariates to account for possible geographical gradients in abundance or stratum-level effects that were not captured by our other landscape-scale covariates.

Using the Distance software line transects were placed systematically with a random start within each survey stratum, using the "Systematic Segmented Trackline Sampling" design class within the automated design component of the software.