Sampling parameters for selection of Primary Sampling Units
Details
Encodes information about the selection of Primary Sampling Units in multi-stage sampling, used in analytical design based estimation. Information is encoded in three tables.
The SampleTable encodes information about the sample of sampling units:
- Stratum
Mandatory, chr: Identifies the stratum the sample is taken from. Treat unstratified sample as single-stratum sampling (provide only one stratum.
- N
Optional, num: The total number of PSUs in Stratum (total available for selection, not total selected)
- n
Optional, num: The number of PSUs 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.
- FrameDescription
Optional, chr: Free text field describing the sampling frame.
The SelectionTable encodes information abut the selection of sampling units for sampling:
- Stratum
Mandatory, chr: Identifies the stratum the PSU is taken from.
- Order
Optional, num: Identifes the order of seleciton. May be necessary for inference when selections are not independent (e.g. FSWOR)
- SamplingUnitId
Optional, chr: Identifes PSU. NA encodes non-response
- InclusionProbability
Optional, num: The inclusion probability of the PSU
- HTsamplingWeight
Optional, num: The normalized Horvitz-Thompson sampling weight of the PSU
- SelectionProbability
Optional, num: The selection probability of the PSU
- HHsamplingWeight
Optional, num: The normalized Hansen-Hurwitz sampling weight of the PSU
- SelectionDescription
Optional, chr: Free text description of the PSU.
The StratificationVariables table encodes information about which columns in the sampleTable are stratification variables (if any):
- Stratum
Mandatory, chr: Identifies the 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 could 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.