IndividualSamplingParametersData: Individual Sub-Sampling Design Parameters
In StoXProject/RstoxFDA: Fisheries Dependent Analysis with RstoX

IndividualSamplingParametersData

R Documentation

Individual Sub-Sampling Design Parameters

Description

Sampling parameters for selection of a sub-sample of individuals

Details

Encodes information about the selection of a sub-sample of observations from individuals, used in analytical design based estimation. A sub-sample is simply a sample of a sample. This data type is intended to represent the final stage of sampling in multi-stage sampling, and therefore has a reference to the Sample it was taken from ('SampleId'). Apart from that there is no principal difference from single stage sampling. All stratification is specified within the sample identifed by 'SampleId', and all sampling probabilites are specified within strata.

The SampleTable encodes information about the sample of sampling units:

SampleId: Mandatory, chr: Identifies the sample the sub-sample is taken from.
Stratum: Mandatory, chr: Identifies the within-sample stratum the sub-sample is taken from. Treat unstratified sample as single-stratum sampling (provide only one stratum. All strata with strata size > 0 must be reported for each SampleId.
N: Optional, num: The total number of individuals in Stratum. For unstratified sampling, the total number of individuals in the sample the sub-sample is taken from.
n: Optional, num: The number of individuals selected from the Stratum
SelectionMethod: Mandatory, chr: 'Poission', 'FSWR' or 'FSWOR'. The manner of selection for use in bootstrap or inference of inclusionProbabilities, selectionProbabilites, co-inclusion probabilities or co-selection probabilities.
SampleDescription: Optional, chr: Free text field describing the sample that is subsampled.

The SelectionTable encodes information abut the selection of sampling units for sampling:

SampleId: Mandatory, chr: Identifies the sample the sub-sample is taken from.
Stratum: Mandatory, chr: Identifies the within sample-stratum the individual is taken from.
Order: Optional, num: Identifes the order of seleciton. May be necessary for inference when selections are not independent (e.g. FSWOR)
IndividualId: Optional, chr: Identifes individual. NA encodes non-response / observation failure
InclusionProbability: Optional, num: The inclusion probability of the individual
HTsamplingWeight: Optional, num: The normalized Horvitz-Thompson sampling weight of the individual
SelectionProbability: Optional, num: The selection probability of the individual
HHsamplingWeight: Optional, num: The normalized Hansen-Hurwitz sampling weight of the individual
SelectionDescription: Optional, chr: Free text description of sampling unit.

The StratificationVariables table encodes information about which columns in the sampleTable are stratification variables (if any):

SampleId: Mandatory, chr: Identifies the sample the stratification applies to
Stratum: Mandatory, chr: Identifies the within-sample stratum. In addition the Stratum is identified by the combination of all other columns on this table.
...: Mandatory if present (may not contain NAs), chr: Additional columns in the sampleTable that are stratification variables.

Optional columns may be NA.

The selection methods available for 'SelectionMethod' are explained here:

Poission: Poission sampling. Selection is performed randomly without replacement, and each selection is performed individually. Sample size is not fixed, and 'n' represents the expected sample size.
FSWR: Fixed sample size with replacement. A random selection of a fixed sample size 'n' is chosen with replacement
FSWOR: Fixed sample size without replacement. A random selection of a fixed sample size 'n' is chosen without replacement. Order of selection should be specified in the 'selectionTable'

The SelectionProbability is defined as:: The probability of selecting the sampling unit when it was selected from the population.
The HHsamplingWeight:: The normalized sampling weight, or the fraction of the stratum represented by the sampled unit when estimating with the Hansen-Hurwitz strategy: 1 / (SelectionProbability*Q) , where Q is the sum of the reciprocal of the SelectionProbabilites for the sampled units. For equal probability sampling with replacement, this is simply 1/n, where n i sample size.
The InclusionProbability is defined as:: The probability of the sampling unit being included in the sample.
The HTsamplingWeight:: The normalized sampling weight, or the fraction of the stratum represented by the sample when estimating with the Horvitz-Thompson strategy: 1 / (InclusionProbability*P), where P is the sum of the reciprocal of the InclusionProbabilites for the sampled units. For equal probability sampling without replacement, this is simply 1/n, where n is sample size.