Understand sampling uncertainty
How sampling design changes precision
Optimal Sample Allocation. A headcount is not always the same as an independent information count. Clustering, unequal weights, and stratum allocation can increase or reduce precision.
1Describe the population structure2Apply the declared design adjustment3Report both nominal size and effective precision
Method used
Proportional nh∝Nh; Neyman nh∝NhSh.
Neyman allocation minimizes mean-estimator variance when per-unit costs are equal and SD inputs are credible.
What the result cannot establish
A design effect summarizes a specified design; it does not correct selection bias, nonresponse, coverage error, or a poorly defined target population.
Assumption: Rounded allocations preserve the requested total and at least one unit per stratum; operational constraints and unequal costs require a custom design.
Quick guide
How to use this calculator
- Enter the observations, probabilities, model parameters, or summary statistics requested by the visible labels.
- Keep every value on the same scale and confirm that the selected sampling relationship, distribution, and tail convention match the question you are investigating.
- Read the result together with its assumptions and interpretation. Statistical output summarizes uncertainty under a model; it does not repair biased data or establish causation.
Calculation method
How the optimal sample allocation calculator works
Proportional nh∝Nh; Neyman nh∝NhSh.
Neyman allocation minimizes mean-estimator variance when per-unit costs are equal and SD inputs are credible.
Worked example
Optimal Sample Allocation example
A larger, more variable stratum receives more observations under Neyman allocation.
Proportional nh∝Nh; Neyman nh∝NhSh.
Supported inputs
Precision and limits
Model and design
Rounded allocations preserve the requested total and at least one unit per stratum; operational constraints and unequal costs require a custom design.
Numerical scope
Inputs use double-precision numerical methods with guarded domains. Datasets accept up to 10,000 finite plain-decimal values. Extremely large parameters or probabilities deep in a numerical tail may require specialist statistical software.
Interpretation
Neyman allocation minimizes mean-estimator variance when per-unit costs are equal and SD inputs are credible.
Decision boundary
The calculator does not validate how data were collected, diagnose dependence or bias, choose a scientifically meaningful effect, or replace review by a qualified statistician for consequential research, medical, regulatory, safety, or policy decisions.
Privacy
Entered values and calculated results stay in this browser and are not sent to an analytics service.
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